Behavior Genetics, Vol. 8, No. l, 1978

ABSTRACTS Behavior Genetics Association Abstracts MICHAEL ANDREGG. University of Minnesota. Learning in Drosophila? Experimental evidence for response perseveration and some theoretical considerations. Populations of D. pseudoobscura have been artificially selected for differences in geobehavior as measured by Hirsch-Hadler geotaxis mazes. During the course of my work with two such populations I subjected samples of flies to surgery directed at potential geosensing organs. Among other observations, a most curious result was obtained. Flies drawn from a geonegative population, which were deprived of their distal antennae, yielded nearly uniform distributions in the mazes. How might a binomial machine generate a uniform distribution? One possibility is that the flies of these samples showed response perseveration, that is, that they had a tendency to repeat previous responses in the multi-trial maze. A statistical model is constructed. The observed distributions of flies sans antennae are interpreted in terms of this model, which suggests that the flies would have had to repeat prior responses on in excess of 80% of trials. Such a high degree of response perseveration coupled with nearly neutral average geotaxis scores suggests a short term learning process.

DARIUS BAER AND DEBORAH BANKER. I n s t i t u t e f o r B e h a v i o r a l G e n e t i c s , U n i v e r s i t y o f C o l o r a d o . S e l e c t i o n f o r i n t e r - m a l e a g g r e s s i o n in mice: A progress r e p o r t . Dominance in male mice as measured by high mating success has been shown to be c o r r e l a t e d w i t h low t a i l wounding. The f o l l o w i n g experiment is being performed to determine whether i t is p o s s i b l e to e s t a b l i s h s e l e c t e d l i n e s d i f f e r i n g w i t h r e s p e c t to c o r r e l a t e s o f Darwinian f i t n e s s . A p i l o t study i n d i c a t e d t h a t s e x u a l l y n a i v e male mice p a i r e d f o r seven days w i t h females were s i g n i f i c a n t l y more a g g r e s s i v e in i n t e r - m a l e e n c o u n t e r s . Beginning w i t h a f o u n d a t i o n p o p u l a t i o n o f HS (heterogeneous) mice, a w i t h i n - l i t t e r , singlesex s e l e c t i o n s t u d y was i n i t i a t e d to produce r e p l i c a t e l i n e s o f hi gh, c o n t r o l and low a g g r e s s i v e n e s s . The c r i t e r i o n f o r s e l e c t i o n i s the d i f f e r e n c e between t a i l b i t e s i n f l i c t e d on the males o f the s e l e c t i o n l i n e s and t a i l b i t e s i n f l i c t e d on t h e i r opponents, which a r e d e r i v e d from an FI cross between the C57BL/61bg and BALB/clbg i n b r e d s t r a i n s . F o l l o w i n g seven days o f sexual p r i m i n g , the males a r e t e s t e d at about 60 ~ y s o f age in a p a i r e d encounter f o r 24 hours in a t r i a d cage s i t u a t i o n .

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0001-8244/78/0100-0085505.00/0 9 1978 Plenum PublishingCorporation

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Results through the fourth generation of selection indicate l i t t l e separation of the lines. This may be due to the correlation between the selection factor and Darwinian fitness and to the fact that dead losers in the low lines cannot be used for mating. A significant correlation exists between weight differences and t a l l b i t e differences in the selection mice and t h e i r opponents such that more t a i l bites are suffered by mice with a greater weight disadvantage. Further, there exists a degree of w i t h i n - l i t t e r resemblance with respect to t a l l bites. Short-term aggression variables, as measured in the f i r s t 15 minutes of pairing, correlate highly wlth the selection variable. Supported in part by grant CFTR-}O76 from The Council for Tobacco Research and in part by a grant from the Council on Research and Creative Work, University of Colorado.

ELLEN BARKER, University of Minnesota. Birth year~ b i r t h order and interchild i n t e r v a l : Effects on childhood |Q. This analysis of factors affecting childhood IQs within families considers the effects of year of b i r t h , b i r t h rank and family size, the length of time between the births of siblings, and the sex of an individual. Using the Reed and Reed (1965) pedigrees, childhood I Qs and b i r t h dates were ascertained for a sample of families. Families were included when childhood IQs were available for at least one parent and two of the o f f spring unless there was only a single offspring. There appears to 6e a s t a t i s t i c a l l y s i g n i f i c a n t effect of b i r t h year on the childhood IQs of individuals born in the f i r s t half of this century. For the f i r s t 16OO IQs examined, b i r t h year and childhood IQ correlated -.24. The effect of b i r t h year is the same for males and females. Birth order and interchild interval are being examined on|y in the offspring generation where more childhood IQs are avaiiab|e. These individuals were born between 1920 and I950. For families of two or more, b i r t h order effects are not as |arge as the e f f e c t of year of b i r t h . Zajonc (1975) has hypothesized that longer intervals between the births of siblings would lead to higher IQs than would be observed when the intervals between births were short. In this sample the effect of interchild interval appears negligible.

Supported by a grant from the Minnesota Human Genetics League and NIMH grant MH-IO679.

F. H. BENOFF. Virginia Polytechnic I n s t i t u t e andState University. Hypothalamic uptake of [3H] - testosterone in l i n e s of chickens selected f o r high and low mating a b i l i t y . The uptake and retention of radioactive testosterone by hypothalamic tissues were measured in lines of chickens selected 17 generations f o r high and low cumulative number of completed matings and in the unselected randombred population from which the selected lines originated. T r i t i a t e d testosterone was injected i n t o 5-week old cockerels in one of two ways:

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(a) as l a b e l l e d testosterone in corn o i l and (b) as l a b e l l e d and unlabelled testosterone in corn o i l . Birds were then s a c r i f i c e d at e i t h e r 30, 60, 120, or 240 minutes a f t e r i n j e c t i o n . Radioactive testosterone uptake by blood and hypothalamic tissue expressed in d i s i n t e g r a t i o n s per minute (dpm) was the measurement c r i t e r i o n . No s i g n i f i c a n t differences were found between hormonal treatments or among lines f o r blood and f o r hypothalamic dpm, whereas s i g n i f i c a n t differences f o r time of s a c r i f i c e were found f o r both. Line by time of s a c r i f i c e r e l a t i o n s h i p s indicated t h a t although there were no differences among lines f o r blood dpm, there were differences between lines f o r hypothalamic dpm. This indicates differences in the a b i l i t y of these tissues to concentrate and r e t a i n testosterone. Supported in part by NSF grant GB 40060 to P. B. Siegel.

GREGORYCAREY, JAMES SHIELDS, AND IRVING I. GOTTESMAN. University of Minnesota ( f i r s t and third authors) and the Institute of Psychiatry, London (first and second authors). Preliminary report on a clinical-genetic study of the obsessional and phobic neuroses in twins. A follow-up of 26 twins with a hospital diagnosis of obsessional neurosis or obsessional personality and of 21 twins with a hospital diagnosis of phobic neurosis or phobias has just been comp]eted. These twins form a consecutive series of twin admissions to the Maudsley and Bethlem Hospitals in London who have received these types of diagnoses at one or another attendance there. The full data analysis has not been completed and awaits the completion of blind ratings of the case histories. Provisional results, based on the first author's assessment, find a strikingly high concordance for obsessional and phobic features in the cotwins of MZ probands, although the neurotic state itself has a lower concordance. For DZ twins, both obsessional and phobic, concordance for the neurotic state and for obsessional and phobic features is less than it is in MZ twins. Case history material is presented to illustrate the type of "spectrum" cases found in the cotwins and to demonstrate how modeling cannot account for the concordance. The correspondence between these results and those of other twin series with obsessional and phobic twins will be discussed. Supported by NIMH grant.

BONNIE FRANK CARTER. The University of Connecticut, Genealogical analyses of cerebral laterality and dyslexia. Cerebral lateralization indices (Ll's) fo~ visually presented (tachistoscopic) and audltorily presented (ds linguistic and non-linguistic stimuli were determined for all immediate members of thirteen selected families exhibiting dyslexia (N = 76; age range 6 to 52). This report focuses on the language laterality data, particularly the unexpected finding of intraindividual dissociation or directional discordance for visual

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and auditory assessments. Data from previous investigations relevant to this cross-model dissociation are presented, with particular mention of the disparate interpretations suggested by the statistics of correlations as opposed to concordance rates. Family and individual data from the current study are presented in support of the validity of visual-auditory discordance for language laterality. Supported by PHSgrant liD 08195-02 and by a grant from The Connecticut Research Foundation,

LOUISE CARTER-SALTZMAN. University of Washington. The relationship between temporal integration of the speech signal and cognitive performance in adoptive and biological families. The results of numerous behavior genetic studies of intellectual functioning have led to the general conclusion that a substantial proportion of the variance in cognitive a b i l i t i e s can be attributed to genetic factors. L i t t l e e f f o r t has been invested, however, in the attempt to specify what heritable process variables might underiie and mediate cognitive functioning. In the present investigation, 552 adult members of adoptive and biological families were tested on measures of specific cognitive a b i l i t i e s , measures of general IQ~ and measures of perception, integration and memory for auditory verbal information. Performanceon a delayed auditory feedback task (200 msec delay) and an auditory d i g i t span memory task were found to predict performance on a range of other cognitive tasks for the sample as a whole. When the sample was broken down by family membership, differences in the relationships among measures were revealed, with fathers and daughters exhibiting the greatest s t a b i l i t y . The extent to which speech production was impaired under conditions of DAF was found to be highly heritable, as was auditory digit span memory. Sensitivity to temporal order information and its involvement in the processes of perception and storage of auditory l i n g u i s t i c signals may be a crucial component to certain kinds of i n t e l lectual a b i l i t i e s . The developmental implications of this p o s s i b i l i t y w i l l be discussed. Supported by NIH Grant HD-O8016 to Drs. Sandra Scarf and Richard A. Weinberg and NIMH Training Grant 2TOl MH06668-17 to the Institute of Child Development~ University of Minnesota.

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ANDREW N. CLANCY AND DELBERT D. THIESSEN. University of Texas. Social functions of the Harderian gland pheromone in the mongolian gerbil Meriones unguiculatus. The Harderian gland, found in numerous vertebrate species~ is located behind the eyeball and secretes complex lipids and pigments when autogrooming occurs, Recent evidence suggests these secretions operate as attractant pheromones that facilitate social contact in the Mongolian gerbil. Social and reproductively related functions of the attractant pheromones of the Harderian g]and were studied in the gerbil. Experimental verification that Harderian secretions facilitate mutual post-grooming facial investigation and social contact between animals was obtained, extending earlier observations. Experiments were performed which suggested that the attractant properties of Harder's pheromone function to increase social cohesion between parents and their offspring by allowing pups to localize and orient more precisely to parents and the nest site.

ROBERT L. COLLINS. Jackson Laboratory. Toward understanding the inheritance of asymmetry: the genes for "right" and "left" may be identical. That human left- and right-handedness are heritable characters is beyond dispute. Hand preferences of children resemble those of their parents and full-sibllngs. Of itself, this information neither affirms genetic nor nongenetic hypotheses of inheritance. Either could account for this heritability. Implicit in each genetic model for the inheritance of asymmetry advanced thus far is the notion that the directions are coded by one or more sets of alternative genetic alleles that reside in the genome of individuals exhibiting asymmetry. The past half-century of published data on handedness in human twins, and the experimental studies of paw preference in inbred mice, provide strong evidence against such formulations. Genes appear to be "left-right agnosic." Clearly, either the senses of asymmetry are maintained by processes of nongenetic inheritance, or genetic models differing markedly from prior ones must be considered. The following suggests that alternative genetic approaches may prove useful. Consider that genetic variation may affect the strength or weakness of lateralization, although genes themselves are indifferent to leftright. If the initial senses of asymmetry arise as an outcome of a seemingly random, though not necessarily equiprobable, process, and if individuals exist in worlds favoring the expression of a single direction, then genes affecting laterallzation may mimlc the inheritance of left and right. Note however that the genes that increase right are the same genes that increase left. And genes that decrease right are the same genes that decrease left. More simply, the genetic alleles for left and right are found to be identical. A better understanding of asymmetries arises when they are viewed as vector, rather than scalor, variates, and when attention is directed at the genetic influences affecting the degree of laterallzation. Evidence supporting this formulation was obtained by considering sex differences in the expressed lateralities of mice tested in biased worlds. Supported by NIGMS grant GM-23618,

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RAYMOND R. CROWE, MD, AND HOWARDB. ASHBY, MD. Department of Psychiatry, University of Iowa. A pedigree study of unipolar depression. We studied a five generation family in which there were multiple cases of affective disorder and suicide. We interviewed 7l family members and obtained family history data on the others. Diagnoses were made by three independent clinicians with a high degree of agreement. ResearchCriteria and Family History - Research Diagnostic Criteria were used for personal and family histories respectively. Sixteen family members were diagnosed as having affective disorder (including unipolar depression, suspected depression, and bipolar affectlve disorder) or had suiclded. Two cases of bipolar illness were diagnosed but were f e l t to arise from sources outside the kindred. The family is notable because few large kindreds of unipolar illness have been reported.

CURTIS K. DEUTSCH AND J. K. BELKNAP. University of Texas at Austin. Neurosensitivity to tert-butanol in C57BL/6J and DBA/2J mice. Acetaldehyde has been hypothesized to mediate the presumed conditioned aversion and neurosensitivity effects of ethanol in inbred strains of mice. DBA/2J mice have been reported to possess greater taste aversion and less neurosensitivity to ethanol than do C57BL/6J mice. These differences have been reported to exist in the same direction for DBA/2J and C57BL/6J with regard to acetaldehyde. This paper reports the use of tort-butanol, an alcohol which is not metabolized in vivo; thus--implication of a toxic metabolite in the determination of neurosensitivity is obviated. The two strains C57BL/6J and DBA/2J were administered 1.49 g/kg tert-butanol IP, and were tested for differences in fall time, induc--ti~n time, and blood and brain levels of tert-butanol upon waking. Each measure indicated that the C57 s t r - ~ d i s p l a y e d greater neurosensitivity than did the DBA strain. Naive animals from both strains were injected with 0.97 g/kg tort-butanol IP and administered the grid-test. Again, the C57 strain displayed greater neurosensitivity than did the DBA strain. These results, concordant in direction with data reported in the literature with regard to ethanol administration, indicate that differences in neurosensitivity need not arise as a consequence of intermediate metabolism. Supported by NIDA Grant DA 01215-01 awarded to J. K. Belknap.

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BRUCE C. DUDEK. State U n i v e r s i t y of N e w York at B i n g h a m G e n e t i c d i f f e r e n c e s in s e n s i t i v i t y to g a m m a - b u t y r o l a e I m p l i c a t i o n s for alcohol p s y c h o p h a r m a e o g e n e t i c s , P r e v i o u s r e s e a r c h and present data suggest that only beh a v i o r s with a strong m o t o r i c component are d i f f e r e n t i a l l y a f f e c t e d by ethanol in the LS and SS mice s e l e c t i v e l y bred by M c C l e a r n and K a k i h a n a for d i f f e r e n c e s in e t h a n o l - i n d u c e d loss of r i g h t i n g reflex. N e u r o e h e m i e a l and p h a r m a c o l o g i c a l data have s u g g e s t e d a role for b r a i n c a t e c h o l a m i n e s in these d i f f e r ences. This p a p e r r e p o r t s the d i f f e r e n t i a l ~ffects of gammab u t y r o l a c t o n e (GBL) w h i c h is k n o w n to inhibit impulse t r a n s m i s sion in d o p a m i n e r g i c neurons, At three doses (550~ 700, and 850 mg kg -I) GBL p r o d u c e d longer loss of r i g h t i n g reflex in LS than in SS mice. The two lines also showed q u a l i t a t i v e d i f f e r e n c e s in r e s p o n s e to these doses. A second e x p e r i m e n t i n v e s t i g a t e d the ability of amp h e t a m i n e to a t t e n u a t e the effects of low dose GBL a d m i n i s t r a tion. R e s u l t s are d i s c u s s e d in terms of the p h y s i o l o g i c a l locus of action of the o r i g i n a l M c C l e a r n and K a k i h e n a s e l e c t i o n for ethanol s e n s i t i v i t i e s . S u p p o r t e d by NSF grants BMS 73-01499 and BNS 75-16118 A01. S p o n s o r e d by John L. Fuller. ton. tone:

ROBERT H. DWORKIN. Harvard University.* Genetic and environmenta] influences on person-situation interactions. Genetic and environmental influences on person-situation and personmode of response interactions for anxiety and dominance were investigated in an adult twin sample. For anxiety, evidence of significant genetic variance was found for the person-situation interaction and the personfl~de of response interaction. For dominance, evidence of common familyenvironmental influences was found for the person-situatlon interaction. Sex differences in the pattern of findings were a|so examined. The data indicate that the factors influenoing person-situation interactions vary depending on the trait studied. In addition, the data illustrate that behavior-genetic research can address important theoretical questions about the nature of personality. Supported by an NSF Grant for Improving Doctoral Dissertation Research in the Social Sciences and an NIMH Graduate Traineeship.

*Now at the Department of Psychology, Cornell University

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RICHARD FRIEDMAN, SONJA B. HABER, AND JUNICHI IWAI. Medical Department, Brookhaven National Laboratory, Upton, New York. Behavioral correlates of genetic predisposition to experimental hypertension. Behavioral correlates of the genetic predisposition to hypertension were examined in two selected lines of rats. Specifically, general activity level and exploratory behavior were measured in Dahl-hypertension sensitive (S) and Dahl-hypertension resistant (R) rats. All subjects were normotensive at the time of testing. In addition to genot~pe, sex and age effects were analyzed. The testing apparatus was a black plexiglas arena diagonally bisected into two chambers. The walls of one side were eovered with novel stimuli, while the other side was left uncovered. The entire arena was situated on top of a selective activity meter which recorded movements by stimulation of electromegnetic cells. Latency to first novel side entry, number of side to side crossings and total novel side time were measured in addition to locomotion. The data from these four dependent variables were subjected to a principal components factor analysis with Varimax rotation. Two main factors emerged which were most easily interpreted as general activity level and stimulus exploration. Further analyses indicated no genotypic differences in exploratory behavior. However, the general activity level of S rats was significantly higher than R rats. Significant age and sex effects were also obtained. Since genetic heterogeneity still exists within the S and R rat lines, the relevance of the behavioral correlations remains somewhat obscured. Further testing, in conjunction with an extensive inbreeding program~ will clarify the importance of behavioral c h a r a c t e r i s t i c s as early indications of the susceptibility to hypertension.

J O H N L. F U L L E R A N D P A T R I C I A W O J D Y L A . S t a t e U n i v e r s i t y of N e w Y o r k at B i n g h a m t o n . Poster Presentation. S e l e c t i o n for b r a i n w e i g h t in m i c e and c o r r e l a t e d e f f e c t s . In 1969 s e l e c t i o n w a s i n i t i a t e d for h i g h (H), i n t e r m e d i a t e (M) and l o w (L) b r a i n w e i g h t r e l a t i v e to b o d y w e i g h t . The f o u n d a t i o n s t o c k o b t a i n e d f r o m T.H. R o d e r i e k w a s d e s c e n d e d f r o m an 8 - w a y c r o s s of i n b r e d s t r a i n s . S e l e c t i o n for the H and L l i n e s w a s m a d e by b r e e d i n g s i b l i n g s of i n d i v i d u a l s w h o s e b r a i n w e i g h t s d e v i a t e d m o s t f r o m a p r e d i c t e d value, b a s e d on the reg r e s s i o n of b r a i n on b o d y w e i g h t . In the M l i n e s i b l i n g s of i n d i v i d u a l s w i t h the l e a s t d e v i a t i o n w e r e s e l e c t e d . Approxim a t e l y o n e - h a l f of the m a t i n g s in each g e n e r a t i o n w e r e r e t a i n e d in the b r e e d i n g p r o g r a m . M a t i n g s of i n d i v i d u a l s w i t h c o m m o n grandparents were excluded when possible. At SII m e a n b r a i n w e i g h t s in mg w e r e : H, 549; M, 479; L, 448. Selection was t h e n r e l a x e d b u t the d i f f e r e n c e s persisted. At S i 7 m e a n w e i g h t s w e r e : H, 580; M, 504; L, 458. F e m a l e b r a i n s w e r e a b o u t 10 mg heavier than males. R e v e r s e s e l e c t i o n in l i n e s H and L for three generations was effective. F e r t i l i t y as m e a s u r e d by p r o p o r t i o n of p a i r s p r o d u c i n g o f f s p r i n g s and n u m b e r of live p u p s p e r l i t t e r s h o w e d no S y s t e m a t i c c h a n g e f r o m S 1 to S12, Heavier b r a i n s a p p e a r to be a s s o c i a t e d w i t h m o r e r a p i d m a t u r a t i o n ~ less a g g r e s s i v e b e h a v i o r and b e t t e r l e a r n i n g of some tasks, S u p p o r t e d b y N S F g r a n t BMS 7 3 - 0 1 4 9 9 .

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Galvin, Nancy J. University of Iowa. Gene differences alter sensory system and central nervous system function in crickets. Orthopteran insects perceive sound stimuli up to 2000 Hz by way of filiform sensory hairs located on abdominal cercal appendages. From the base of each hair a single sensory neuron enters the terminal ganglion through the cercal nerve and innervates interneurons, among which are giant interneurons involved in an escape response. Bentley (Science: 187, 1975) examined the cercal sensory system in a cercai hairless mutant and found n o evidence that the mutant gene influenced function in the giant interneuron. We produced lines of the cricket, Acheta domesticus, with high and low filiform hair densities using 5 generatibns of bidirectional, within family selection. Crickets selected for high densities of cercal hairs show fewer giant interneuron spikes in response to sound pulses than do crickets selected for low hair densities. A reasonable hypothesis is that increased hair densities are associated with increased synaptic densities on giant interneuron dendrites. Greater density of synapses would increase membrane conductance during synaptic activity and lower the postsynaptic response to a standard stimulus. Regardless of the mechanism of this gene influence on central nervous system function, our results demonstrate that selection procedures provide a powerful and perhaps necessary complement to the use of mutations in genetic analysis of nervous system function in behavior. ARLEEN GARFINKLE AND STEVEN G, VANDENBERG. I n s t i t u t e f o r Behavioral Genetics, University of Colorado. DevelopmentOf Piagetian logico-mathematical concepts: Somepreliminary findings of a twin study.: A twin study is currently being conducted in which 200 samesex, 4- to 889 twin pairs are being administered the PIagetian Mathematica] Concepts Battery, Raven Colored Progressive Matrices, PeabodyPicture Vocabulary Test, immediate and delayed visual memory tests and l a t e r a l i t y measures. In addition, the parents complete the Moos Family Environment Scale and the A t t i tudes Toward Education Questionnaire. Somepreliminary results are presented on a sample of 44 MZ and 410Z twin pairs of equal sex d i s t r i b u t i o n . Both the age and socioeconomic status (SES) distributions in the present sample are negatively skewed, with older twins and higher SES more prevalent. Age is highly correlated with test performance on these cognitive measures; Ss also exhibits influence. With age partiaIled out of cognitive test performance, between- and w i t h i n - p a i r variances and intraclass correlations are presented for DZ and MZ pairs. With age part i a I l e d out, correiatlons between performances on various cognitive measures are presented. Supported in part by a grant from the Council on Research and Creative Work, University of Colorado, and in part by a grant from the Spencer Foundation.

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MARY COOK GERVAIS. Institute for Behavioral Genetics, University of Colorado. Litter effects and effect of litter size on the open-field behavior of three lines of mice. Mice from three replicated lines (high activity~ control, low activity) of six generations (I, 5, IO, 15, 20, 25) of the DeFries selection experiment were tested in the open field. Analyses of data on 2,705 animals were performed to assess the effects of litter membership, line, and natural litter size and post-weaning group size on activity and defecation scores. Large litter effects, or significant differences among litters, were found, and the subsequent statistlcal tests employed corrections for the nesting of litters within treatments. The results of these analyses revealed that llne effects increased greatly through the course of selection, and that neither litter size nor post-weaning group size had significant effects on open-

f i e l d a c t i v i t y or defecation. Supported in part by a University of Colorado Fellowship and in part by NIMH training grant MH-ilI67.

BENSON E. GINSBURG AND CYNTHIA S. SCHOTTE. The University of Connecticut. Genetic differences determining the capacities for social behavior among wolves and dogs. Our observations on groups of captive wolves allowed to develop without tutors from the wild demonstrate that they show all of the behaviors characteristic of natural packs insofar as the conditions of a restricted range and artificial feeding permit. These include the individuation of soelal roles, the development of a communication system, and specialized behaviors including courtship, the feeding of older juveniles, the establishment of a preferential breeding structure, among other attributes. In raising and handling individual wolves, it is clear that their capacity to solve problems involving sequential manipulations exceed that of any dogs tested, and that their orientation in space takes account of cues on vertical surfaces to a much greater extent than is seen in domestic dogs. The latter, though able to form packs, lack the capacity to Individuate clear social roles, do not court or pair-bond as wolves do, reproduce at an earlier age~ and have a fragmentary and variable communication system. These characteristics correspond roughly to those of juvenile wolves, and the hypothesis that the dog is essentially a neotenous wolf appears to fit these observations. Supported by NIMH grant ~Kq27591-01.

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H. H. GOLDSMITH. University of Minnesota. Laterality and twins. This theoretical paper treats Istera|ity differences in MZ and DZ cotwins in terms of a simple model representing various causal influences. Evidence suggests that these causes are heterogeneous and may include partial asymmetry reversal and subtle early brain damage in MZ's as we]] as genetic differences in DZ's. The notion that unusual laterallzation is associated with the MZ twinning event itself is critically evaluated. Limitations and possibilities of using twins in ]aterality research are discussed along with the issue of the comparability of latera]ity in twins and singletons. The possible biasing effect of laterality differences in the generalization of twin study results to singletons is considered. Supported in part by the Dight Institute for Human Genetics.

LYNN T. GOLDSHITHAND DON M. MOHR. University of Minnesota. Cognitive abilities in Turner's syndrome individuals. Turner's syndrome individuals (45,XO) have previously been observed to have an unusual profile of cognitive abilities best c~mracterized by normal verbal skills and abnormally low spatial ones. This pattern has been ascertained largely by comparing the performance of Turner's syndrome patients on standardized tests with the existing normative data for the tests. In this study we sought to: (i) compare test performance of Turner's syndrome individuals against that of other family members to determine whether the cognitive profile of Turner's syndrome girls observed in earlier studies might have been due in part to familial factors rather than entirely due to the chromosomal anomaly, and (2) describe in more detail the specific cognitive character of Turner's syndrome individuals. This profile was investigated by administering a battery of cog-nitive tasks to Turner's syndrome girls and their families. The present preliminary report is based on data from the ten families already tested. Comparisons of performance by Turner subjects, male and female siblings were made for four spatial tasks (PMA Spatial Abilities, Vandenberg mental rotations, Money & Alexander Road Map Test, Semmes et. al. route finding task). In all four tests, mean performance by the Turner group was below that of both groups of siblings; there was generally no difference between level of performance for male and female sibling groups. For some tasks the range of scores within the Turner group was extremely large, with some subjects performing very poorly and others very well. Although these are only preliminary data, this finding of wide distributions in scores on some spatial tasks may indicate that the overall spatial deficit described earlier as a cognitive characteristic of Turner's syndrome may be an artifactual description based onanalyses of group data rather than individual cases. Research supported by NIMH Small Gran= 1 R03 MH28668-01.

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M I K E G R A H A M a n d D E L T H I E S S E N . T h e U n i v e r s i t y of T e x a s . S e x u a l D i m o r p h i s m a n d I n d i v i d u a l D i f f e r e n c e s in t h e U l t r a Sonic S i g n a l i n g of M o n g o l i a n G e r b i l s (Meriones u n g u i c u l a t u s ) . A d u l t a n d n e o n a t a l g e r b i l s s h o w p a t t e r n s of u l t r a s o n i c communication t h a t are s p e c i e s s p e c i f i c , sex s p e c i f i c , a n d individual specific. Adult gerbils emit ultrasounds during social encounters; the b e h a v i o r is s e x u a l l y d i m o r p h i c , w i t h a d u l t m a l e s e m i t t i n g m a n y m o r e s o u n d s t h a n females. The h i g h e s t r a t e of e m i s s i o n is o b s e r v e d d u r i n g e n c o u n t e r s b e t w e e n m a l e s , a n d the r a t e v a r i e s i n v e r s e l y w i t h t h e s e v e r i t y of t h e a g g r e s s i v e b e h a v i o r . M o r e o v e r , t h e o c c u r r e n c e of u l t r a s o u n d s , a n d the r a t e of e m i s s i o n in s o c i a l s i t u a t i o n s is p o s i t i v e l y c o r r e l a t e d w i t h locomotor activity and ventral scent marking. Exposing adult m a l e s Or f e m a l e s to a r t i f i c i a l l y p r o d u c e d u l t r a s o u n d s s t i m u l a t e s i n v e s t i g a t o r y b e h a v i o r a n d c a u s e s i n c r e a s e s in l o c o motor activity. The s e a r c h for the f u n c t i o n of the u l t r a s o u n d s , and investigations into t h e e t i o l o g y of i n d i v i d u a l v a r i a t i o n in the b e h a v i o r , led to d e v e l o p m e n t a l s t u d i e s of i n f a n t u l t r a sounding. O b s e r v a t i o n s of n e o n a t e s r e v e a l e d the d e v e l o p m e n t of sex and i n d i v i d u a l d i f f e r e n c e s in the r a t e of u l t r a s o u n d i n g in t h e f i r s t t h r e e w e e k s a f t e r birth. T h e r e s u l t s i n d i c a t e an i n t e r p l a y of e n v i r o n m e n t a l and g e n e t i c f a c t o r s in the e t i o l o g y and e x p r e s s i o n of u l t r a s o n i c communication. Supported

by N I M H

Grant

MH

14076-10.

SONJA B. HABER I, EDWARD C. S L M ~ L 2 , AND RICHARD C. SIIEP@IAN2. iBrookhaven National Laboratory and 2Miami University. Effects of environmental complexity on stimulus reactivity and locomotor activity in mice. The synergistic relationship between genotype and environment and its effect on stimulus reactivity and locomotor activity were investigated. The specific experience under investigation was the modification of the ear!y rearing environment in mice. Twenty mating pairs, I0 of each of two genotypes, BALB/cBy and C57BL/6By, were set up in one of two types of environments: complex -- multi-level cages with novel and complex stimuli; or simple -- standard laboratory cages. The offspring of these matings (40 females and 40 males) were placed into one of four rearing conditions: complex-complex (cc) -- mice weremaintained in the complex environment until testing at 55 days of age; complex-simpl e (cs) -- mice were reared in a complex environment until one week prior to testing at which time they were placed in a simple environment; simple-comple ~ (sc) -- mice were reared in a simple environment until one week prior to testing at ~s time they were placed in a complex environment; or simple-simple (ss)-- mice were reared in a simple environment until testing. All subjects were tested for stimulus reactivity and locomotor activity using the original procedure of Simmel and Eleftheriou (in press). Ordinal interactions bet~een genotype

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97

and e~vironment were obtained. Specifically a gene x enviro~z~ent x sex interaction provided information concerning the behavior of C57BL/6By females similar ~to that obtained in a previous experiment. The results are discussed in terms of this and other interactions. This experiment, in conjunction with one previously reported, allow a definitive star.ant concerning the malleability of stimulus reactivity and locomotor activity as a function o~ ge~e-environment synergism.

CAROLE HANSULT, DONNABALOPOLE AND CHARLES SCOUTEM. Effects o f p r o | a c t~m~ dexamethasone, and Cortlcostero~e on materna| aggression and infant care. Prevlous studies have indicated that proiactin may be essential ~n prometing maternal aggression in normally non-aggressive C5781/6J mice but has relatively little effect in BALBc/bCRGL mice. This extension of that study investigates the possible permissive role of corticosterone in both maternal aggression and care. Because of the location of our lab BALBc/bJ mice were substituted for BALBc/bCRGL, They did not show the attack frequencies that the California mice did. The two were compared. Subjects were tested for aggression against a male intruder. C57's which attacked and BALBJs which did not were discarded. Mothers were tested the day they gave birth and given either proiactin, prolactin/corticosteroid, corticosteroid, dexamethasone or saline once a day for seven days and then tested for aggression. During this time maternal care was observed. BALBc/bJ mice showed no effect of any treatment. C57's showed a depression i~ materna| care under dexamethasone and an ~ncrease in aggression under both pro~act{n and prolactin/ corticosterone. BALBc/bCRGL mice showed a decrease in maternal care under dexamethasone but no other effects. It appears, then, that BALBc/bCRGL and BALBc/bJ mice have developed significant differences in maternal aggressi0n over the years and in maternal care.

GREGORY HARSHFIELD and EDWARD C. SIN~dEL, ~ a m i University. Relationships between Heart Rate ~nd Stimulus Reactivity in LG/J ~/~d DBA/2J Mice. In previou~ studies combining multivariate and Behavior genetic ~nalyses~ we found that locomotor activity can be distinguished experimentally from stimulus reactivity, and is under separate genetic control. The present study is the first in a series designed to investigate the physiological correlates of stimulus reactivity (the initial responses of an animal to novel/complex stimuli). Heart rate was monitored for six males snd six females each of two strains of i n b ~ d mice: DBA/2J and LG/J during testing of stimulus reactivity. DBA's had low stimulus reactivity scores (long latencies to approaching novel stimuli and 10w exploration scores) a l t h o u ~ they maintained fairly high activity scores. H ear~ rate associated with initial and later apl~roaches to novel stimuli in the DBA's was highly

98

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unstable and high in magnitude. LG's, on the other hand, had high stimulus reactivity scores accompanied by low and stable heart rates throughout the testing situation. Physiological strategies and implications for future genetic research are discussed.

DAVID A. HAY. La Trobe University, Australia. The use of genetically homogeneous populations to study invertebrate learning. Organisms such as Drosophila and freshwater planarians have one unique advantage in studying the determinants of learning ability. By inbreeding and by cloning respectively, large n u ~ e r s of genetically homogeneous individuals can be obtained and a variety of behavioural tests run on different but identical organisms. Some studies have been carried out on the planarians, but it has been necessary to obtain much information on the ecology before their behaviour can meaningfully be analysed in the laboratory. This approach has been used mainly to study the determinants of maze performance in D. melano~aster, where genetic differences in associative cond[tionfng have been isolated from other behaviours such as sequential alternation and a right-left turning bias. Artificial selection over 25 generations for differens components of maze behaviour confirm there are at least three genetically independent behavioural processes involved in the m a z e - r u n n i n g ability of Drosophila. A new maze design for Drosophila is described, which permits the easy construction of mazes of many different configurations. Some results from these mazes provide further evidence for strain differences in an associative learning ability whereby mere passage through the maze constitutes some form of reinforcement. These results also cast doubt on the validity of many maze studies of Drosophila photo- and geo- taxes.

Joseph P. Hegmann, and Ann Blakley. University of Iowa. Gene differences alter placental transport of amino acids in mice, Females of the C3H/HeJ mouse strain 12 days pregnant with C3H inbred or CD hybrid pups and females from the DBA/IJ strain carrying 12-day old embryos of the DBA or DC hybrid genotypes were injected in the tail vein with I miorocurie of lq-C-labeled alpha aminoisobutyric acid (AIB). Mothers were sacrificed 10, 20, or 40 minutes after injection and embryos and individual placentae were dissected from the uterus, weighed, solubilized at about ~5 degrees C overnight, and counted. Transfer of AIB

Ab~r

99

increased across time for both genotypes of m o t h e r b u t b o t h u p t a k e of A I B b y p l a c e n t a e and t r a n s f e r o f A I B f r o m p l a c e n t a e to embryos were influenced by gene differences, Placentae from C3H m o t h e r s are l a r g e r b u t t a k e u p a n d t r a n s f e r l e s s A I B than those from D B A m o t h e r s ~ t r a n s p o r t b y p l a c e n t a e to h y b r i d o f f s p r i n g (CD a n d DC) e x c e e d s t h a t to i n b r e d s (CC a n d DD). Assuming that AIB transfer is r e p r e s e n t a t i v e of t r a n s f e r o f o t h e r s m a l l m o l e c u l e s b y mice, t h e s e r e s u l t s s u g g e s t a mechanism for heterosis and maternal e f f e c t s o n m o r p h o l o g i c a l and b e h a v i o r a l c h a r a c t e r i s t i c s and t h e y demonstrate the extent to w h i c h maternal genotype d e t e r m i n e s o f f s p r i n g e n v i r o n m e n t in e m b r y o n i c m a m m a l s .

GEORGE A. HEIKF/~S, Fergus Falls State Hospital, Differential fertility for males ~elated to the externalizing-internalizing personality dimension using MMPI scales, In a prospective study relating personality variables as measured by the l ~ I to subsequent questionnaire reported marriage and legitimate fertility variables~ a fertility differential was found between groups of male traiversity graduates classified as "externalizers" and those classified as "internalizers" on the basis of single high point MMPZ code classes, Subjects were 491 male graduates of the University of Minnesota who graduated in the mid 1950's and who had completed a valid ~iPI during their college careers, i~r~iage and fertility information was obtained at a median interval of 17 years after the MMPI was given. The Externalizati0n-lnternalization dimension was obtained by Achenbaeh as the first principal factor extracted from a factor analysis of check-list descriptions of a sample of disturbed adolescents, It was expected that males having high points on one of the "Externalizing" scales (the 3-Hy, 4-Pd, 8-Sc, and 9-Me scales) would tend to have the highest fertility and marriage rates, Those with highpoints on the "Internalizing ~ scales (the 0-Si, 2-D, 5-Mr, or 6-Pa scales) were expected to have the lowest fertility and marriage rates, Chi-square tests showed highly significant differences between E~ternalizers and Internalizers in the expected direction in proportions ever reproducing~ proportions ever 1~arried. and ~overall legitimate fertility. Supported by NIMH gra~t l~l 10679 and grants from the University of Minnesota Computer Center,

100

Abstracts

NORMAN D. HENDERSON. Oberlin College. Genetic analysis of exploratory activity during the night cycle. To provide further evidence of this investigator's position that interactions of genotype with age, environment, or testing conditions can often be predicted when one has some knowledge of natural behavior or the organism in question, a number of measures of exploratory behavior in mice were taken during the night cycle. It was predicted that any shifts in the genetic pattern of activity measured at night would be toward greater directional dominance for high exploration. The results of a triple test cross analysis involving eight inbred strains and appropriate F 1 crosses was compared to results obtained earlier using these same measures during afternoon testing. Exploratory behavior in test situations involving a maze and a multi-compartment box did show a shift toward greater directional dominance. The genetic analysis of open field activity, however, showed a striking similarity to that obtained during daylight testing. Two out of three isn't bad. Several lines of evidence suggest that locomotor behavior in an open field may reflect a different weighting of underlying factors than activity meastlres taken in more complex situations. Despite this, thereappears to be a general activity component eo=m~n in all tests, which shows a high degree of additive genetic variance. Differences in behavior patterns across test situations appear to be more influenced bynon-additive genetic effects. Supported b y N S F

Grant 28017.

Henry, Kenneth R. University of California, Davis. Interaction of age and albinlc alleles on recovery of the auditory nerve volume-conducted response from acoustic trauma. Co,genie 35 day old cl/c I (albino), +/c I, cP/c p (platinum), +/cP, c /ch (himalayan), ~/~W, +/+, and 16 day ~id--cl/c I, +/c__l, and +/~ C57BL/6 mice were exposed to an acoustic priming stimulus. Their volume-conducted, computer averaged auditory nerve response (PI) was determined from lOdb to 70db before, i minute after, and 2 days following acoustic stress. To compensate for the effects of anesthesia, surgery, and growth, their PI amplitude and latency measures were subtracted from those of matched, nonexposed littermate controls. Noise i,naediately decreased amplitude and increased latency. This effect was most pronounced at 10w sound levels, mimicking the electrophysiological correlates of noiseinduced recruitment of loudness in man. No age differences were observed in the auditory nerve response to 30db - 70db click stimuli, hut the older mice showed a greater decrement at 10db than at 30db, while the mice in the critical age for acoustic priming showed a more severe response to 30db than to i0 db. These younger mice developed hyper-recruitment within 2 days, whil~ the 35 day old mice did not. The +/c I was heterotic to the +/+ and cl/c for most of these effects, although ~he direction of this heterosis reversed from 16 to 35 days. The +/~P was also generally heterotic to the +/+ an d ~P/~P, although this was not true for comparisons involving the himalayan allele. At 70db, the PI response had dual peaks, as first described by Haythorn. Changes of the time between the major energy peaks

Abstracts

I01

of the click stimulus were found to produce a corresponding interval change between the dual PI peaks. Acoustic trauma resulted in an immediate loss of this frequency following response in 139 of the 147 mice, but this response returned more quickly for mice in the critical period for acoustic priming.

W. F. HOLLANDER AND W. J. MILLER. Iowa State University. Observations on pigeons having congenital head tremor associated with the "Sideburns" mutant. The phenotype "sideburns" was discovered in Iowa in 1952. Affected individuals typically have whorled or reversed feathering of the mandible and sometimes also other facial areas. The eye cornea commonly is somewhat bulged, but vision seems unaffected. A tendency to respiratory rale seems significantly greater than among normal pigeons. Breeding experiments suggest a partially dominant gene with incomplete penetrance. Data from outcrosses of sideburns x normal shows somewhat fewer mutants than expected by a I:i ratio, especially where the sideburns parent is male. Matings of sideburns x sideburns have given still more deviant ratios and have so far produced at least i0 sideburns progeny showing continuous marked head tremor. It is hypothesized that these are hemozygotes, but testing is difficult because of poor breeding ability. These birds learn to eat, drink, and find their way around fairly well. They are not ataxic, but flying is erratic. The head movements vary from a rocking to a shaking, about 4 to I0 per second. A neurological basis has not been found. Motion pictures will be shown. Supported i~ part by the Iowa Agriculture and Home Economies Experiment Station project no. 1940. Sponsored by Pamela Kaufman.

Joseph M. Horn, Lee Willerman, and John C. Loehlin. University of Texas at Austin. Heritability of intelligence: evidence from the Texas Adoption Project. IQ test scores from the Revised Beta Examination were obtained from 342 women who gave their children up for adoption within three days of birth. These test scores were correlated with the Wechsler or Stanford-Binet IQs of their 3 year-old or older adopted-away children who had been placed in 299 adoptive families. This correlation was compared to the correlations between the Beta IQ scores of the adoptive fathers and mothers and the IQs of their adopted and natural children from the Wechsler or Stanford Binet. The comparisons support the hypothesis of a significant degree of genetic influence upon individual differences in intelligence. For the full-scale IQ~s of the children, all the biological parent-natural child correlations were larger than the adoptive parent-adopted child correla~idns~ Since the Beta is primarily a measure of performance IQ the same~orrelations were examined using only the performance IQ of the children. ~esults very similar to that

102

Abstracts

for full-scale IQ were obtained indicating that pers IQ is under appreciable genetic influence. The influence of selective placement on these correlations is discussed. Supported by U.S. Public Health Service Grant MH-24280.

CRAIG JENSEN. Pace University~estchester. Increase in learning measures with increased brain weight in heterogeneous mouse lines. Three lines of unseleeted heterogeneous mice were tested for learning and activity measures in active avoidance acquisition and extinction, water maze discrimination lea~Ing and reversal learning, operant discrimination, and passive avoidance %asks. Open field activity was also measured, Low to moderate correlations (absolute values of .21 to ,47) between brain weight and learning scores were obtained for all butthe passive avoidance task, The signs of the correlations always indicated a positive relation between brain weight and learning. The correlation of brain weight with the m e a n ~ score of the six measures from the four tasks was .54 (~ < .01). A moderate correlation between brain weight and activity was found only in the open field, ~evious across-order and across-specles research has suggested a posltlve relation between brain weight and learning. The ~esults reported here extend this relation to va~latlon between brain si~eand learning within one species, Supported b y N S F Grant GB-24827 to John Fulle~,

RONALD C. JOHNSON, University of Hawaii; JOHN C. DE FRIES, University of Colorado; FRANK M. AHERN, University of Hawaii; and MING P. MI, University of Hawaii. Resemblances of collateral relatives in cognitive abilities. The present report is an addition to the literature on resemblances of collateral relatives in cognitive abilities. Data are presented showing the resemblances between 200 biological uncles and aunts and their nephews and nieces, between 200 biologically unrelated uncles and aunts and these same

nephews and nieces, and between68 sets of cousins (256 individual cousins), on a number of measures of cognition. Resemblances are such that a genetic explanation of the results appears a reasonable one. Supported by NSF grant GB 34720 and NICHHD grant HD 06669 t o G. C. Ashton, J. C. DeFries, R. C. Johnson, G. E. McCiearn, H. P. Hi, M. N. Rashad, S. G. Vandenberg, and J. R. Wilson.

Abstracts

103

KENNETH K. KIDD, MARY ANN RECORDS, AND JUDITH R. KIDD. Yale University School of Medicine. The transmission of stuttering. Data on over 350 families of male stutterers confirm that stuttering is a familial trait. The lifetime incidences of "ever stuttered" (with a minimum duration of at least 3 months) are roughly 5% for males and 1.5% for females. Preliminary analyses of the data on first degree relatives of male probands show the frequency of affected among the male relatives is 183/904= .203• and the frequency of affected among the female relatives is 54/852=.063• Strong evidence also exists for familial "transmission" of at least a predisposition to stuttering. Male probands were classified according to parental stuttering and the incidences among the remaining first degree relatives examined. When neither parent stuttered, the risks for siblings and offspring are ]7.3% for males and 4.3% for females. When the father stuttered, the risks are 33.3% for males and I0.2% for females. The increases are significant (p < .Of). A genetic explanation seems likely and various models will be discussed. Supported by NIH grant NS-I1786-03.

THOMAS W. KLEIN AND RAYMOND B. CATTELL. University of California, Davis, and University of Hawaii. Genetic and environmental components in objective measures of personality. The High School Objective-Analytic Personality Battery, measuring twelve "objective" personality traits, was administered to 71 pairs of identical twins, 92 pairs of fraternal twins, and 369 pairs of full sibs. Estimates of genetic variance, environmental variance and common environmental covarianee were obtained from both the comparison of MZ and DZ twins and from MZ twins and full sibs. While the former analysis yielded only two estimates of genetic variance which reached statistical significance, the estimates of environmental variance reached statistical significance for all 12 factors. Those estimates of environmental covariance which reached statistical significance were all positive. This latter result is in sharp contrast to the results of a parallel analysis carried out on the 14 primary factors of the High School Personality Questionnaire, which was completed by approximately 80% of the present sample. In those analyses, the effect of common environmental factors appears to differentiate the members of the sib pairs. A comparison of the results of the MZ-DZ analyses with those from MZ twins and full sibs suggested a greater effect of common environmental variables for DZ twins than for full sibs.

104

Abstracts

ROBERT C. lACY AND CAROL B. LYNCH. Wesleyan University. Genetic analysis of characters contributing to temperature regulation in Mus musculus. I. Covariance of relatives. An understanding of the complex influences on bebmvioral and physiological interactions underlying the components of adaptive syndromes mast ultimately rely on genetic analysis. Appropriate breeding designs can elucidate the nature and extent of genetic influences contributing to both the expression of individual traits and the correlations among thegn. Thermoregulatien provides an ideal system for genetic analysis since the behavioral and physiological characters involed have been thoroughly described for small mm~als, and n~ch is known about envirorm~tal influences on these traits. One design which provides estimates of heritabilities of individual traits as well as genetic correlations m ~ n g multiple traits involves measurement of a variety of potentially thermoregulatory traits on parent and offspring generations. Measurements were made on about 280 litters of a heterogeneous stock of laboratory mice (HS/Ibg). Heritabilities (S.E. 's < .I) of basal metabolic rate, nonshivering thermogenesis, body temperature, and weight of interscapular brown adipose tissue were low (< .I), those of nesting, thermal preference, and food constmption were intermediate (about .3), and that of body weight was high (.4). Estimates of genetic correlations were generally imprecise, except for a few comparisons involving traits with relatively high heritabilities. From comparison of their heritabilities, we conclude that physiological heat production mechanisms have been pushed to their genetic limits by natural selection, while behavioral mechanisms, inherently more flexible, may have been selected toward intermediate optima. Supported by NIH grant (~21993 to C.B. Lynch. JOHN C. LOEHLIN, LEE WILLERMAN, AND JOSEPHM. HORN. University of Texas at Austin. WeChsler Verbal and Performance IQs in adoptive families. In 299 adoptive families from the Texas Adoption Project, 122 of which also contained biological children of the parents, correlations were obtained between parents and children and among siblings for Verbal and Performance IQs from the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Intelligence Scale for Children (WISC). Correlations between parents and their biological and adopted children for Verbal IQ generally followed the pattern expected i f this t r a i t is under additive genetic influence, that is, the biological parent-child correlations were in all cases larger than the corresponding adoptive parent-child correlations. This was also true of father-child correlations for Performance IQ, but not of mother-child correlations. Thus Performance IQ showed less clear evidence of genetic influence. For the sibling correlations, on the other hand, i t was Performance IQ that gave the stronger evidence of h e r i t a b i l i t y , and Verbal IQ for which biologically related children were not more alike than unrelated children. These paradoxical results were further borne out in an analysis of WAIS/WISC subtests. Three verbal subtests, Information, Comprehension, and Vocabulary, showed evidence of h e r i t a b i l i t y in motherchild and father-child correlations, but not in sibling correlations. Other subtests, including Digit Span, Picture Arrangement, and Arithmetic, showed conflicting patterns for father- and mother-child comparisons. Various possible explanations for these results (including sampling error) are considered. Supported by USPHSgrant MH-24280.

Abstracts

105

CAROL B. LYNCH AND ROBERT C. LACY. Wesleyan University. Genetic analysis of characters contributing to temperature regulation in Mus musculus. If. Response to selection. Establishment of lines of mice genetically divergent with respect to nesting has resulted in a]teratlon of genetically associated traits which allows both investigation of the makeup of the adaptive syndrome of temperature regulation, and the dissection of mechanisms underlying thermoregulatory ability. About 400 mice from the 13th generation of a replicated bidirectional selection experiment (with control lines) for nesting were tested on a variety of presumed thermoregulatory traits. For selection, all mice were tested at 2i~ and the selection index was total weight of cotton pulled from the food hopper across 4 days of testing (old nests were removed each day). At the 13th generation, high-nesting mice averaged 50g of cotton compared to 8g used by low-nesting mice. The most consistent difference between the selected l~nes was a difference in food consumption, even though the mice had no access to nesting materia]. High-nesting mice exposed to cold ate less (l.23 g/g body weight vs 1.37 g/g body weight; t = 5.46~ p < .001), while maintaining at least the same thermogenlc capacity. In addition, body weight showed a slight but significant positive correlated response at this generation (27.5g vs 26.8g; t = 2.3l, p < .05). Comparison of the results of this experiment with those from parent-offspring comparisons indicates that correlated responses can detect small genetic correlations for traits with intermediate or high herltabilities, while parentoffspring cross-covariance detects only relatively large genetic correlations, but can accomplish this even for traits with heritabilities not demonstrably different from zero. Supported by NIH grant GM 21993 to C. B. Lynch.

ADAM P . MATHENY, J R . , AND ANNE B. DOLAN. University of Louisville. Asynchronies in c h i l d r e n ' s behavioral development: Embedded synehronies influenced by genetics. It is a commonplace observation that any p a r t i c u l a r aspect of childrents b e h a v i o r can change markedly f r o m one behavioral setting o r age to some o t h e r behavioral setting o r age. F u r t h e r , different behaviors show a lack of consistency in t h e i r relations as examined by setting o r age. These asynchronies of development were examined for m e a s u r e s of t e m p e r a m e n t and mental development obtained from twins at periodic ages (18, 24, and 30 months). As individuals, the twins were found to d e m o n s t r a t e asynchronies of development. Separated into identical and f r a t e r n a l p a i r s , however, the within-pair profiles of behavioral s i m i l a r i t y revealed that synchronous p a t t e r n s of behavior underlay the asynchronieso The r e s u l t s a r e discussed in r e f e r e n c e to genetic aspects of developmental c o n s i s t e n c y even in the face of change. Supported by NIMH grant MH-23884 and NICHD grant BD-07200. R . S . Wilson.

Sponsoredby

106

Abstracts

STEPHEN C. MAXSON, THOMAS R. DeFANTI, AND DONNA L. KONIECKI. University of Connecticut. A spontaneous seizure mutant in C57BL/10Bg mice. A mutation causing repeated, spontaneous seizures occurred in C57BL/10Bg mice. These repeated convulsions result in death. They first appear between 40 and 70 days of age. These spontaneous seizures resemble "psychomotor" epilepsies, and although it is not a reflex epilepsy to either visual or auditory or vestibular or pain stimuli, there are interactions of this mutation and genes for susceptibility to audiogenic seizures, So far the following neural and genetic aspects of it have been characterized. During the seizure, epileptiform activity is present in bipolar recordings of the cortical electroencephalogram and interictal spiking is associated with "staring" behavior. Also, bilateral lesions of the dorsal hippocampus seem to block the occurrence of spontaneous seizures. Genetic analyses of this mutation are consistent with a recessive inheritance; tentatively the gene is designated as spontaneous seizures (sps). It does not appear to be linked to either albino or dilute or brown loci. Also, there are no gross neural or neurological pleiotropisms. These findings suggest that this mutation may be a valid animal model of at least one type of epilepsy. Supported by USPHS grant RR 00602-05 and a grant from The Grant Foundation, Inc.

MARK G. McGEE. Texas A & M University. Further evidence for a genetic component in the determination of handedness. Recent work in hemispheric specialization suggests that the right cerebral hemisphere is specialized for spatial processing and that males have greater hemisphere specialization than females. This hypothesis has served as a tentative explanation of male superiority on spatial tasks and predicts spatial deficiency in left handers who presumably are less well lateralized than right handers for either spatial or linguistic functions. Empirical data have not consistently supported this expectation, although discrepant frequencies of left handedness as a function of sex and generation, varying degree of bilateral representation among sinistrals, and small sample sizes preclude definitive conclusions. The present analysis tests a prediction that derives from the specialization hypothesis--a positive correlation between degree of lateralization and spatial test performance. The results, along with proportions of right and left handed offspring from five mating types and intrafamilial correlations, provide further evidence for a genetic component in the determination of handedness and the specialization hypothesis as well. Supported by Texas A & M University, Office of University Research Grant # 12811-DPC.

Abstracts

107

HARRY MUNSINGER AND ARTHUR R. JENSEN. University of California, San Diego and Uniyersity of Ca1[fornla, Berkeley. The intelligence of twins. We report analyses on several large samples of published twin IQ scores collected during a review of twln intelligence~ Most of the measurements are Stanford-Binet individual IQ scores. Since these important data were published in older, difficult to obtain journals and because the original analyses were often primitive or incomplete by modern standards, we collected all the IQ scores and applied modern biometrica| methods to them. Specifically, we computed the following for each subsample of twins: average IQ, standard deviation of IQ, average within-palr IQ differences, distributions of within-pair IQ differences, tests of genotype by environment interaction~ and age or sex effects on the twin IQ scores and the withln-pair IQ differences. In addition, we pooled those samples of twin IQ scores within zygosity that did not differ significantly in average IQ or standard deviation of IQ. These pooled samples of identical and fraternal twins were used to estimate the broad heritabl]ity of intelligence. The samples totaled over ]000 pairs of twins including superior, retarded and brain-damaged samples of same-sexed fraternal twins, oppositesexed fraternal twins and identical twins. In addition, we found IQ scores on parents of opposite-sexed fraternal twins, siblings of twins, and even a small sample of orphans. Consistent with earlier results, we found that identical twin pairs are much more similar in intelllgence compared with fraternal twins and that sex of fraternal twin pairs has no effect on their IQ similarity. Moreover, we found evidence of genotype by environment interaction only among brain-damaged twin samples. The absolute withinpair IQ differences were normally distributed for fraternal twins (they formed half a normal distribution--the chi distribution). However, the absolute within-pair IQ differences for the identical twins departed systematically from a chi distribution as the withln-pair differences in intelligence increased. We believe this departure is further evidence that some MZ twins suffered the twin transfusion syndrome. Finally, the pooled samples of twins evidenced high broad heritability of intelligence.

RICHARD H. MYERS AND ARTHUR FALEK. Human and Behavioral Genetics Laboratory. Huntington's disease, a preclinical detection study. Huntington's disease (H.D.) is an incurable hereditary neurodegenerarive disorder of late onset. Since H~ is dominantly transmitted, an individual has a 50% chance of inheriting the disorder from an affected parent. No current diagnostic procedure is able to detect carriers of the H.D. gene prior to the time of clinical onset around 40 years of age. As a result, at-risk persons have no way of knowing whether they carry the geneo The current study investigates a procedure for early detection of the H.D. gene. One of the most characteristic symptoms of Huntington's disease is a progressive worsening of choreiform movement. It is hypothesized that those at-risk persons carrying the H.D. gene will show unusual muscular tremor on a minute scale which is similar to the gross movements of affected persons. The assessment procedure involves the monitoring of muscular tremor by an accelerometer. This instrument detects the spontaneous muscular tremor

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produced by a standard amount of muscular tension. A wave form tremor pattern is produced and recorded by a pen tracing on a constant speed paper strip for visual quantification. The characteristic muscle tremor of affected persons was found to be significantly different from that of normal control subjects on seven visual assessment parameters. A group of at-risk subjects was found to be composed of certain members who resembled the affected persons and others who resembled normal controls on visual assessment of muscle tremor recordings. Recently the muscle tremor signals have been assessed by computer using a Fourrier transform analysis. Again a preliminary group of at-risk subjects has been differentiated into two groups; those that resemble normal controls and those that resemble affected subjects. The computer assessment provides greater objectivity, accuracy and speed of analysis.

RICHARD H. M Y ~ S AND DAVID A SRAFER. Human and Behavioral Genetics Laboratory. Genetic studies of an intergeneric hybrid ape. On August ii, 1975 and again on August 30, 1976 hybrid female apes were born to a female siamang Symphalangus syndactylus and a male gibbon Hylgbates moloch. Both animals continue tO develop without abnormality. No previous primate crosses have been known to occur between the apes or between primate species of different chromosome number. The ~ has 50 chromosomes while the H~lobatesmo!och has 44. As expected, the hybrid or "siabon" has 47. Cytogenetic studies reveal little similarity between the G-band patterns of the two parents (the siamang has not been previously published). No clear chromosomal homologies can be identified. C-band patterns are even more strikingly different. In the gibbon, small pericentric C-bands were revealed, while the siamang was characterized by large telomeric C-bands. Our findings of few chromosomal homologies is remarkable for two reasons. First, biochemical studies have reported that the proteins of the parental species are virtually identical. Second, field studies report that the parental species are highly similar behaviorally. A few distinct morphological differences exist. An unusual relationship between genotype and behavior presents itself. The behavior and structural genes are similar while the banding patterns are drastically different. It is proposed that the morphological differences and the species divergence between these two animals is a result of regulatory gene changes, or position effects produced by chromosomal rearrangements. These rearrangements have influenced behavior only minimally. Sponsored by Arthur Falek.

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109

DONALD J. NASH, MICHELE M. CRIPPS, AND DAVID A. BARNES. Colorado State U n i v e r s i t y . A c t i v i t y in mice selected f o r l a r g e s i z e . The Gooda}e Giant s t r a i n o f mice o r i g i n a l l y was developed by Goodale (]938) in a mass s e l e c t i o n study f o r increased body weight. The s t r a i n has been maintained a number o f years in our l a b o r a t o r y as an inbred s t r a i n by f u l l brothers i s t e r m a t i n g . At 60 days o f age males o f the s t r a i n weigh 41 gm and females 35 gm. The mice have normal body proportions and e x h i b i t no evidence o f obesity. Studies have shown t h a t the mice have a m i l d hyperglycemia w i t h plasma glucose l e v e l s o f over 200 mg/lO0 ml. The mice show no o v e r t c l i n i c a l symptoms but do have a reduced l i f e s p a n and reduced l i f e t i m e reproduction. Tests have been conducted on a number o f behavioral parameters i n c l u d i n g l e a r n i n g , aggression and developmental t r a i t s . The mice are e a s i l y s t a r t l e d and tend to overrespond to novel s t i m u l i . The present study was undertaken to examine a c t i v i t y and e l i m i n a t i o n in the open f i e l d . The study employed a standard Mendelian analysis i n v o l v i n g the parental s t r a i n s , G/Gw and C57 BI/6J, and the FI , F2 and backcross populations derived from them. Locomotion and e l i m i n a t i o n in the open f i e l d were tested a t 60 days o f age. Mice o f the Goodale Giant s t r a i n were r e l a t i v e l y i n a c t i v e in the open f i e l d (mean number of squares entered : 33 compared to 130 f o r the C57 BI/6J mice). Some evidence f o r d i r e c t i o n a l dominance towards the G/Gw s t r a i n was observed in the hybrids. S i g n i f i c a n t maternal e f f e c t s were present f o r body weight but were not evident f o r e i t h e r locomotion or e l i m i n a t i o n .

GILBERT S. OMENN AND BRUCE A. WEBER. University of Washington. Dyslexia: Search for phenotypic and genetic heterogeneity. Dyslexia, or specific reading disability, has been shown in many studies to be familial, though no simple mode of inheritance accounts for all pedigrees. It is likely that the difficulties of genetic analysis are due to heterogeneity within the phenotype. We have undertaken a series of studies of normally intelligent children with dyslexia and their families in a search for phenotypic and genetic evidence of heterogeneity. Family histories with specific attention to difficulties in learning to read and spell and in handwriting were taken for 21 families. School test results were available for probands. Spelling was analyzed and anecdotal information assessed to determine whether visual or auditory difficulties predominated. Among the probands, 13 had predominantly visual problems with phonetic spelllng, while 8 had predominantly auditory problems with notable mispronunciation and sometimes non-phonetic spelling. Visual and auditoryevoked responses were measured on all the probands and some of the family members, seeking neurophysiological evidence of abnormality or asymmetry of response. No significant differences were found between hemispheres, between those with visual and those with auditory predominance, or between

left-handed and rlght-handed i n d i v i d u a l s . A Boder word l i s t of 25 con~nonly misspelled words was given to a v a i l a b l e members of a number of these and other f a m i l i e s . In most cases the s p e l l i n g e r r o r s were phonetic; however, cases of dysphonetic s p e l l i n g errors clustered in certain f a m i l i e s . Beth anecdotal family h i s t o r i e s and s p e l l i n g performances suggest that dys]exic patients may be delineated into subgroups with predominantly visual or predominantly a u d i t o r y impairment and that these subtypes may be under separate

110

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genetic p r e d i s p o s i t i o n . Further neurophysiological i n v e s t i g a t i o n w i l l be required to devise ways of i d e n t i f y i n g cases before learning d i s a b i l i t y becomes obvious. Supported by USPHS grant GM15253.

RICHARD PERLINE AND R. DARRELL BOCK. University of Chicago. A Monte Carlo study of two s t a t i s t i c a l tests for detecting linkage on the Xchromosome between a mendelian character and a major gene for a quantitative character. PerIine and Book have proposed a likelihood ratio test for detecting linkage on the X-chromosome between a mendelian character and a quantitative character governed by a single gene. We now present results of a simulation study to evaluate the power of this method versus a quite d i f ferent method proposed by A. Hlll and generalized by C. A. B. Smith. We find that, on average, about 1/3 to 1/2 as many sibships are needed to detect linkage with the likelihood ratio test as compared to H i l l ' s procedure. But both methods are much affected by I) the size of the sibships analyzed, 2) the value of the recombination fraction, 3) the effect of the major gene, 4) the extent to which the sibs' values on the quantitative t r a i t are correlated because of background polygenlc effects other than the major gene. HOwever, our method requires the identification of mothers who are heterozygotic for both the marker and the major gene, whiie H i l l ' s test only involves identifying mothers heterozygotic for the marker gene. Although we give a scheme for identifying doubly-heterozygotic mothers from the scores of the sons, a simulation study showed i t to have poor accuracy. The necessity for classifying mothers as doubly-heterozygotic is the main limitation of our test. Information about grandparents would be useful in this connection. Supported by N.S.F. Grant BNS76-02845.

ROBERT PLOMIN, JOHN C. DeFRIES AND DAVID C. ROWE. Institute for Behavioral Genetics, University of Colorado. RAY ROSENMAN, Mount Zion Hospital and Medical Center, San Francisco. Genetic and environmental influences on human behavior: Multivariate analysis. The traditional univariate genetic-environmental analysis is generalized to the multivariate case. Rather than analyzing the variance of behaviors considered one at a tlme~ multivariate genetlc-environmental analysis determines the relative contributions of genetic and environmental factors to the covarlance among behaviors. The major advantage of this analysis is its a b i l i t y to reveal the structure and nature of genetic and environmental effects upon behavior. The conceptual framework of multivariate genetic-environmental analysis developed in this report is applied to personality data (California Psychological Inventory) from two samples: 198 pairs of adult male twins (average

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111

age of 55 years) and 170 pairs of adolescent male twins (average age of 15 years). For both samples, the structure of genetic influences differed from the structure of environmental influences. Extraversion was clearly implicated in the genetic structure for both samples; the environmental structure included a leadership factor for the adult males and a sensitivity factor for the adolescent males. The phenotypic factor structure of behavior shows considerable consistency from study to study and from sample to sample, and it is hoped that the genetic and environmental structure of behavior will show similar consistency. Supported by The Grant Foundation and by NIMH grant MH-28076.

ANITA PRUZAN AND PHILIP B. APPLEWHITE. University of Pennsylvania and Yale University. Protein synthesis inhibition alters Dros0phila mating behavior. Fruit fly Drosophila pseudoob@eura v l r g i n A R females mate preferentially with A R m ales when given a choice between AR and o_/_rmaleso However, AR females which mated with o_~_rmales when young show a significant change in sexual selection in favor of or over A R m a l e s in subsequent simultaneous choice tests. Ingestion of foo---dmoistened with 4 ml eyeloheximide (CXM, 400 mg/ml) produces 75% protein synthesis inhibition in the female flies. Females exposed to CXM immediately after their initial copulation with o_/_rmales resemble virgin flies in their choice of mates, and mate preferentially with A~males. Females exposed to CXM before their initial copulatory experience with o_rrmales resemble or--experienced but untreated (no CXM) flies in their eholce of mates, and mate preferentially with o_~rmales. The change in sexual preference shown by females with prior copulatory experience resembles learning in that it is subject to disruption by CXM in ways analogous to those reported in the literature. Supported by NIH Award F32 NS05155-02.

iSRAEL RAMIREZ, The Jackson Laboratory. Why isn't there a behavior genetics of ingestive behaviors? Since so much is known about the physiology and evolution of ingestive behaviors (feeding and drinking), they should be extremely valuable for the study of physiological and evolutionary genetics. Yet, neither physiological psychologists nor behavior geneticists have shown much interest in this area. Although over |40 articles on some aspect of the genetics of ingestive behaviors have been published, most of them were intended to elucidate something else (e.g. diabetes, domestication, lipid metabolism, nutrition, etc.). A disproportionate number of the remaining studies concerned the intake of or preference for various solutions, and comparisons of obese mutants with the ventromedial hypothalamic syndrome. Reviews of ingestive behaviors often display ignorance of the science of genetics (e.g. confusing inbreeding and

112

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selection) even on the rare occasions i t is mentioned. These reviews usually l i m i t discussions of genetics to assertions that a particular behavior is "innate" or that strain differences may exist. Behavior geneticists appear to be even less interested in Ingestive behaviors than physiological psychologists are in genetics. Examination of reviews and books on behavior genetics provides no insight into the reason for this lack of interest. Supported by NIMH Grant MH-I2126.

JOHN RICE, Ph.D., THEODOREREICH, M.D,, AND C. ROBERTCLONINGER~ M.D. Washington University Medical School, Department of Psychiatry. Assortative mating and the multifactorial model with sex effect. We introduced assortative mating into a general version of the multifactorial mode] with sex effect. A phenotypicalIy dichotomous t r a i t is assumed to be determined by an underlying continuous l i a b i l i t y distribution which contains a threshold dividing the two phenotypes. No assumption is made as to the relative importance of genetic and environmental factors in the etiology or transmission of the t r a i t . Separate l i a b i l i t y distributions X} and X2 are assumed for males and females, respectively. The general mode} contains 10 parameters (exclusive of ascertainment parameters), including rM, the correlation in l i a b i l i t y between two mates. The effect of r M # 0 on the random mating parameters is assessed for the general model and also on submodels with smaller numbers of parameters including: (a) the standard polygenic model; (b) the isocorreiational model where X| and X2 are identical, but the thresholds for each are different; (c) the environmental model where Xl and X2 d i f f e r by non-transmisslble environmental factors; (d) the independent model where XI and X2 share some of their tra~smissible factors in common. Expressionsfor the equilibrium correlations and population frequencies are given in terms of the random mating correlations and frequencies. In particular, the increase in populatlon prevalence due to positive assortative mating is given, and a d i f f e r ential increase of parent-offspring and sibling-sibllng correlations is shown. An asymmetry between the two cross-sexed parent-offspring correlations is also found. A psychiatric data set is analyzed using this model. Parameter estimation is done by the maximum likelihood method on nuclear families which are ascertained through affected children. A likelihood ratio test is performed to test for assortative mating. Supported by NIMH grants MH 07081, MHI ~677, MH 00048 and NIAA grant AA O0209.

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113

R O B E R T S. R O D G E R , D a l h o u s i e U n i v e r s i t y . D e s c r i b i n g S e q u e n c e s in B e h a v i o r by M e a n s of F o r m a l G r a m m a r s . In the p a s t , g r a m m a r s w e r e c o n s i d e r e d to be p r e s c r i p t i o n s for h o w s e n t e n c e s s h o u l d be w r i t t e n , but m o d e r n m a t h e m a t i c a l g r a m m a r s can be u s e d to d e s c r i b e any set of c o m p l e t e s e q u e n c e s of d i s c r e t e e v e n t s . For e x a m p l e , g r a m m a r s c o u l d be u s e d to d e s c r i b e p r o t e i n s as c e r t a i n s e q u e n c e s of a m i n o acids. But disc o v e r i n g a g r a m m a r w h i c h w i l l a d e q u a t e l y d e s c r i b e (and p u t a t i v e l y e x p l a i n ) s e q u e n c e s of b e h a v i o r a l acts is d i f f i c u l t . This p a p e r r e p o r t s the use of a n e w l y i n v e n t e d c o m p u t e r p r o g r a m (RLGRAM) w h i c h , g i v e n c o d e d b e h a v i o r s e q u e n c e s , w i l l p r i n t out a r i g h t l i n e a r g r a m m a r to d e s c r i b e them. The p r o g r a m is i n t e r a c t i v e and p r o v i d e s o p t i o n s and g u i d a n c e on p h r a s i n g s t r i n g s of acts t o g e t h er and m a k i n g s o m e acts g r a m m a t i c a l l y e q u i v a l e n t to c e r t a i n others. P h r a s i n g and e q u i v a l e n c i n g acts m o d i f i e s the r e s u l t i n g g r a m m a r a n d t h e s e are the b a s i c o p e r a t i o n s u s e d to m a k e a r i g h t linear grammar more meaningful scientifically. The p r o c e d u r e w i l l be i l l u s t r a t e d u s i n g C r a i g ' s (1943) r e c o r d s of the m o r n i n g s o n g of the w o o d p e w e e ( C o n t o p u s v i r e n s ) , but the m e t h o d c o u l d be u s e d for play, n u r s i n g , r e p r o d u c t i v e , a g o n i s t i c and o t h e r / t y p e s of b e h a v i o r as w e l l as d e s c r i b i n g d i f f e r e n t d e v e l o p m e n t a l s e q u e n c e s of d i s c r e t e s t a g e s . The d i s c o v e r y of m e a n i n g f u l s y n taxes for b e h a v i o r , w h i c h is n o w p r a c t i c a l l y p o s s i b l e for the f i r s t time, o p e n s the door to q u e s t i o n s about the g e n e t i c o r i g i n of g r a m m a r s c o n t r o l l i n g s e q u e n c i n g . B e f o r e the g e n e t i c s can be d i s e n t a n g l e d we m u s t g r a m m a t i c a l l y examine biologically important c l a s s e s of b e h a v i o r in r e l a t e d s p e c i e s and o v e r a r a n g e of d i f ferent habitats. But f u r t h e r r e s e a r c h to f i n d m e t h o d s for the d i s c o v e r y of m o r e e l a b o r a t e g r a m m a r s , e.g. t i m e - d e p e n d e n t gramm a r s and s e l f - e m b e d d e d g r a m m a r s , is a l s o n e c e s s a r y .

DAVID C. ROWEAND ROBERTPLOMIN. Institute for Behavioral Genetics, University of Colorado. An observational twin study of social responsiveness in infancy. One purpose of this study was to explore relationships among dimensions of social responsiveness and to investigate d i f f e r e n t i a l responsiveness by the child to mother and stranger. The contribution of heredity and environment to the development of these dimensions of social responsiveness was examined using the twin methodology. Ninety-two children (mean age 22.2 months) were tested at home in standardized situations consisting of 7 episodes: (1) free play; (2) stranger approach; ( 3 ) p l a y with stranger; (4) play with mother; (5) "cuddling" with mother; (6) "cuddling" wlth stranger; and (7) separation from mother. Separate observers rated the behaviors of each twin using time-sampled and behavior check-list procedures. The two principal investigators acted as strangers in the experimental sessions. The social behaviors were largely independent of one another, though there was some evidence of cross-situational consistency for smiling and positive vocalizations~ Comparisons between intra-class correlations for identical twins (N = 21 pairs) and fraternal twins (N = 25 pairs) revealed that few behaviors directed toward mother were heritable. However, both proximal and distal social behaviors directed to the stranger were heritable.

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BARBAPVk SANDERS. I n s t i t u t e f o r Behavioral Genetics, University of Colorado. Genetic differences in s e n s i t i v i t y to several effects of depressant drugs. In addition to t h e i r depressant or sedative effectS, depressant drugs such as alcohol and barbiturates share numerous other actions. At low concentrations, many of these agents produce activation. Most depressant drugs also have an anticonvulsant action which has been shown to depend upon different structural properties than those responsible for behavioral depression. The results of a number of experiments demonstrate that sensit i v i t y to both the activating actions of these drugs and t h e i r anticonvulsant actions are genetically independent of s e n s i t i v i t y to t h e i r depressant effects (as assessed by loss of r i g h t i n g ) . Although we have found a small but s t a t i s t i c a l l y significant correlation between s e n s i t i v i t y to ethanolInduced behavioral activation and s e n s i t i v i t y to ethano1~induced depression in mice of a genetically heterogeneous stock, we have also found that sens i t i v i t i e s to the activating, anticonvulsant and depressant actions of ethanol and pentobarbital may vary independently across genetically d i f f e r e n t populations. Supported in part by NIAAA postdoctoral fellowship AA-OIg69 and by a grant (72-559) from the Foundations' Fund for Research in Psychiatry.

ROY H. SMITH. ~ary Washington College. Selection for avoidance behavior in ~ i l d MuS muscUlus: An i n t e r i m r e p o r t . Following a stu-"~y Indicatlng intermediate levels of avoidance learning in ~ i l d mice, a r t i f i c i a l selection was begun wlth t ~ twelfth generation of a laboratory-maintained, random-bred population. This population has not shown significant trends toward domestication after thirteen generations of laboratory maintenance. Within-family selection for replicated hlgh, control, and low lines is based on avoidance scores from the last of f i v e days of 30 t r i a l s each by 9e-day old animals. Overall separation is significant at the third selection generation. Meanavoidance scores f o r the two high lines were 25% and 24%, while corresponding scores for the low lines were 9% and 7%. Someasymmetry of response may be Indicated along wlth a general but not severe decrease In l i t t e r size.

KAREN P. SPUHLERAND STEVEN G. VANDENBERG. University of Colorado. Relationship between family environment and children's and parent's cognit i v e performance. To estimate genetic and environmental components of variation in cognlt i v e a b i l i t i e s , 110 Caucasian families were tested using a battery of 15 special a b i i i t i e s tests. Questionnaires to assess socioeconomic status, parental attitudes of raising children~ personal interests and a c t i v i t i e s , and children's response toward parental behavior as components of family environment were administered. By cluster analysis of the t o t a l sample on the a b i l i t i e s tests, four dimensions--Spatial, Visual Memory, Perceptual

Abstracts

! 15

Speed, and Verbal--representing cognitive structure were determined. Patterns of associations between family environment and cognitive ability were analyzed by canonical correlation and multiple regression. Estimates of family environment were found to have differential effects in relation to parent's and children's performance in cognitive ability. Environmental variables acceunted for a smaller proportion of variance in cognitive performance of children in this restricted sample, Results from this study and the family study of cognition conducted in Hawaii will be compared. Supported in part by Postdoctora| Feliowsh!p MHO5346~ and Grants HDO6648 and MHII|67.

RICHARD s STAFFORD AND JANICE DAVIGNON. Brldgewater State College and Boston College, Ar e gender differences in rote memory due to hereditary components? This investigation was conducted to see if there were gender differences between males and females on rote memory tasks and if a difference were found could it be due to hereditary components, Three different rote memory tasks (developed by Dr. Steven G. Vandenberg) were utilized. The first was a word-word association task invo]ving the use of a s i m ~ e m~nuaIIy operated teaching machine. The second also used the machine but was a word-numeral association task. The third task was simple recall of a list of words. The three tasks were given to twins from the LouisviI|e Twin Study: 127 monozygous, 84 dizygous, and i04 heterodizygous (boy-gir]) pairs, ages ]2 to 18, Only the word recall task showed clear evidence for a significant gender difference, although there were trends showing fema|es averaging higher than males for the other two rote memory tasks. The word recall task also indicated the most significant evidence for a hereditary component. Supported by NIH Grant HD 00843, Dr. Steven G. Vandenberg, Principal

Investigator.

BORIS TABAKOFF, 30SEPK YANAI, AND R. F. P.!TZF~NN. Dept. of ~nysiology, University of Illinois Medical Center~ Chicago 60612. Involvement of the noradrenergle ~TE) systems in development ef barbiturate tolerance. C57BI/6 male mice were fed Lab Chow containing sodium phenobarbital (PhB). After consuming the P~-contalnlng diet for 6 or 8 days, mice showed a characteristic withdra%~al syndreme when PhB was removed from the diet. The syndrome consisted of tremors, spontaneous cionic, tonic convulsions and significant hypothermiao These symptoms were found to he mere severe in animals fed the barbiturate ~ ) diet for 8 days compared te these fed B for 6 days. The symptoms were evldent 14 hours after withdra~.~al and abated within 44 hours. Mice 9#ere tested for tolerance to B 44 hours after PhB withdrawal. Sodium pento-

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barbital-14C (PenB, 90 mg/kg) was administered and "sleep time" and body temperature were monitored in B-withdrawn and control (B-free diet) animals. Blood and brain levels of PenB were also monitored throughout the experiment. B-fed animals were demonstrated to have developed both metabolic and functional (CNS) tolerance to B. Since tolerance to ethanol was shown to be dependent on ~he integrity of NE systems in brain, we injected animals with 6-hydroxydopamine (6-OHDA, 50 ug/mouse, icy) prior to chronic feeding with PhB and moni~ toted signs of physical dependence and tolerance as described above. 6-OHDA injection resulted in a 58% depletion of brain NE, but did not significantly affect 5-HT and DA levels. Dependence and metabolic tolerance, which developed after 6 days of B consumption, were not significantly affected by 6-OHDA treatment. However, CNS tolerance was significantly less in 6-OHDA pretreated animals. After withdrawal and injection with a challenge dose (90 mg/kg) of PenB, 6-OHDA-treated mice "slept" 31+4 (SD) min. and exhibited a body temperature depression of 4.6+i.0~ Animals pretreated with artificial CSF "slept" Z4+4 min. and had a bony temperature depression of 2.2+0.6~ Thus, the destruetion of NE systems of 5rain hinders the devel0pmen~of tolerance to B as it does tolerance to ethanol. Supported by NIAAA, NINDS, St. of Ill. ~MH. B.T. is a Sehweppe Foundation Fellow.

STEVEN G. VANDENBERG AND ALLAN R. KUSE. Institute for Behavioral Genetics, University of Colorado. Cognitive scores of individuals in different types of occupations. Carter (1932), Vandenberg and Kelly (1964) and Vandenberg and Stafford (1967) reported greater concordance in vocational interest scores for identical than for fraternal twin pairs and suggested that this is due to greater similarity of "underlying" related abilities and personality traits. The Hawaii study-of environmental and genetic factors in cognition provided an opportunity to see whether the six occupational types proposed by Holland (]966) have different cognitive ability profiles. Two samples were composed of 485 male Americans of European ancestry and 273 male Americans of Japanese ancestry. Analysis of variance gave a significant result for a number of tests, and multiple discriminant functions led to assignment of 30 to 50% of the individuals to the correct occupational type after the few individuals in the "artistic" category were eliminated. This was still true after correction for age and correction for overall socioeconomic status. Implications for future research will be discussed. Supported in part by NSF grant GB-34720 and by NICHD grant HDMH-06669.

J E R O M E H. W A L L E R . University of Pittsburgh. Rapid collect i o n a n d a n a l y s i s of h u m a n c h r o m o s o m e m e a s u r e m e n t s : a lowercost alternative. Fully automated karyotype analysis provides a means of r a p i d g a t h e r i n g of c h r o m o s o m e m e a s u r e m e n t s , b u t the i n i t i a l i n v e s t m e n t is m o r e t h a n $ 1 5 0 , 0 0 0 . We are developing a system t h a t e m p l o y s a t e c h n i c i a n i n s t e a d of a n o p t i c a l s c a n n e r a n d

Abstracts

! 17

uses a large computer only for long-term data storage. The equipment consists of a Hewlett-Packard 983@A programmable calculator with 32K bytes of read-write memory (and three readonly memories), an Elographics E241 digitizer, and a photographic enlarger. Points along the chromosome may be digitized from a photographic enlargement or from the projection of a 35 mm. slide. We have developed programs which allow data collection, local or remote storage, recall and analysis, and remote plotting of a diagrammatic karyotype. Total cost for the hardware is less than $30,000. Pairing of autosomes, detection of the X and Y, and detection of unpaired chromosomes are possible without using a large computer. Given technical improvements in chromosome banding and given reliability of the input device, it is feasible to use this system in small clinics feeding a central data storage hank. If associations between minor chromosomal differences and behavioral phenotypes are to be found, this will be a useful tool. Supported by the General Research Support Grant Graduate School of Public Health.

~RSG)

to the

GLAYDE W H I ~ E Y AND GARY P. HOROWITZ. Florida State University. Dissociation of alcohol and morphine preference among C57BL mice. Most C57BL/6 sublines of inbred mice prefer ethanol in twobottle ethanol versus water preference tests. However mice of the C57BL/6A subline were reported to not prefer ethanol when bred and tested in Alberta, while C57BL/6J mice bred in Maine and tested in Alberta did prefer ethanol (Poley, Behav. Genet. 1972, 2, 245-248). To ascertain the possible genetic or environmental basis for this interesting difference, we obtained C57BL/6A and C57BL/6J mice from Alberta and Maine, respectively. We then raised and tested their descendents under comparable conditions in our laboratory. The subiine difference in ethanol preference was observed, thus strongly supporting the previously suggested genetic base. All C57BL sub!ines s to date in our laboratory, including the Alberta-derived subline, strongly prefer morphine in two-bottle saccharin-morphine versus water preference tests. The dissociation between ethanol and morphine preference displayed by C57BL mice of the Alberta subline may be of importance with regard to commonalities of alcohol and morphine effects. Supported by NIDA grant DA 00828 and NIMH training grant MH 11218.

118

Abstracts

J.R. WILSON, G.E. McCLEARN, AND R.C. JOHNSON. University of Colorado and University of Hawaii. Ethnic variations in use and effects of alcohol. Using a 369-1tem questionnaire, we obtained data concerning use of alcohol from 3717 Americans living in Hawaii, Informational, personality and attltudina} items were answered by all, including teetotalers; alcohol use items were answered only by current oN former drinkers. Compared to data on Americans of Caucasian descent, reports ~Obtained from Americans of Chinese or JapaneSe descent indicated (1) a higher proportion of teetotalers, (2) fewer very heavy drinkers, and (3) higher frequency of facial flushing after imbibing. "Hapa-Haoles" (those with one Oriental and one Caucasian parent) resembled Caucasians on (1) and (2), but resembled Orientals on (3). Comparing current users with former users, we found that former users reported more symptoms (e.g., hangovers~ headaches, dizziness, anxiety, numbness in hart s~feet) associated with alcohol use, as well as more problems (e.g., affected work, affected spouse or other family members, accidents, arrests, attempted suicide). Other analyses are now in progress and may be reported. Supported by NIAAA grant AA-01762.

RONALD S. VTILSON. University of Louisville. Twins and siblings: Comparisons of developmental trends during i n f ~ c y . A large number of infant twins have been followed longitudinally since bir~h, and measures of mental development have been obtained at periodic ages (8, 6, 9, 12, 18 and 24 months, then aunually thereai~er). In addition, infant siblings born subsequently into the twin families have been recruited and tested on exactly the same schedule, These siblings furnish an ideally matched singleton control group for evaluating the effects of t~vinness as such ( i . e . , prenatal and perinatal influences) on measures of developmental status during infancy. The data for each sibling are matched with the corresponding data for the twins to estimate the e~ent of the twins v initial lag, and the course of subsequent recovery. The lag/recovery data for mental development are further e~amined in reference to the birth size and gestational age of the twins, then plotted in relation to their physical growth during infancy. The twins' within-pair concordance is determined for the trends in physical growth and mental development; then the sibling is paired with each twin to provide a measure of twin-sibling concordance for the same trends. This index of concurrence among family offspring reveals the extent to which they follow a common developmental path during infancy, Some illustrative curves for several twin-sibling sets are presented in Figures 1 and 2. ~ r a c l a s s correlations are computed and the results are discussed in reference to the determinants of e a r l y mental development: p r e natal and birth factors, common home environment, degree of genetic similarity, and the distinctive experiences of twin v s . singleton, Supported by NIMH ~Tant MH-23884 and NICHD ~rant }ID-07200.

Abstracts

119

CHAP~ES J. WYSOCKI, J O ~ NYBY; AND GLAYDE k~ITNEY. Florida State University. C o n d i t i o n e d taste aversions: Genotype by o l f a c t o r y b u l b e c t o m y interaction. The d i s r u p t i v e effects of olfactory b u l b e c t o m y upon conditioned taste aversions reported in the literature range from large to nonobservable, both between and within species, Some of this v a r i a b i l i t y may be due to genetic factors. Using housemice, we tested the ability of C57BL/6J, AKR/J and their reciprocal F 1 hybrids to condition an aversion to saccharin u s i n g lithiun~ chloride. All genotypes were tested both with and without bilateral olfactory bulbectomies. Genotypic differences were observed in saccharin preference with C57>FI>AXR. These preferences were not affected by olfactory bulbectomy. As expected, all shamo p e r a t e d genotypes exhibited a marked saccharin aversion after lithium chloride conditioning regardless of normal preferences. While o l f a c t o r y b u l b e c t o m y had little effect upon the ability of AKR's to c o n d i t i o n an aversion, this o p e r a t i o n severely disrupted C57 conditionability. The effects upon F c o n d i t i o n a b i l i t y were intermediate. The d i f f e r e n t i a l effects o~ b u l b e c t o m y on d i f f e r e n t genotypes may be due to sensory and/or n o n s e n s o r y factors. Supported by NIMH grant MH-051i6 and NINDS grant NS-05259.

and training

grant MH-11218

JOSEPH YANAI. Lab Developmental Neurobiology, Department of Biological Sciences, Purdue University (present address: University of 111inois Medical Center). Stereologic studies on strain and sex differences in the rat's brain. The brains of female and male Wistar (W) rats were larger than the brains of Long-Evans (LE) rats at all ages and males had larger brains than fenmles (p < .001). These differences did not correlate with differences in body weight. Brains of female and male LE and W rats age 60 days (N = 48) were perfused with 10% neutral formalin and cut and stained with hematoxylin and eosin. Matching sagittal sections were selected for the study of the cerebellum, hlppocampus and the o|factory bulbs. Brains from a similar group of 48 animals were prepared according to the Golgi-Cox method and were used for the study of Purklnje ceils. Males had a 5.7% larger cerebellar area than females (p < .001). This difference was mostly due to a 6.1% difference in the area of the molecular layer and a 6.2% difference in the granule cells layer (p < .OOl). Males also had more granule cells (8.1%, p < .05) and Purkinje cells (7.2~, p < .05) than females. The strains were similar in the area of the cerebellum, but LE had more Purkinje cells (9.6%, p < .01), packed more densely (II.1%, p < .01) than W cells. The results of the Golgi preparation suggest that the dendritic tree of the Purklnje cells was larger in the LE strain (10.5%, p < .05). There were no sex differences for the hippocampus and the olfactory bulbs, The area of the hippocampus did not differ between strains but W had a longer and thus thinner granule cell layer (15.2%~ p < .001). The hippocampal granule ceils were packed more densely in W strain (8.9~, p < .05).

120

Abstracts

The olfactory bulb granule cells layer of W was larger than LE (14.9~, p < .05). Such anatomical differences may be correlated in subsequent studies with behavioral differences. A recent study suggests that the strain LE which possesses a greater number and larger Purkinje cells also perform better in motor tasks. Supported by USPHS grant 5 TOl-HDO0427.