Social and Behavioral Sciences Commons^™

Of Dogs And Bonds, Jeffrey R. Stevens

Department of Psychology: Faculty Publications

In four of Charles Darwin’s classic works (Darwin, 1859, 1868, 1871, 1872), the domestic dog (Canis familiaris or Canis lupus familiaris)¹ featured prominently, offering key examples to illustrate his ideas about evolution, domestication, comparative behavior and cognition, and emotional expression. Darwin held a clear fondness for dogs, and when replying to letters detailing the “sagacity” of dogs, he remarked “I can believe almost anything about them” (Darwin, 2014). Despite the early interest in their behavior and cognition by a number of leading scientists, dogs were rarely subject to serious investigation as a study species for 150 years. …

Serotonin 5-Ht2a And 5-Ht2c Receptors Regulate Rat Maternal Behavior Through Distinct Behavioral And Neural Mechanisms, Jun Gao, Lina Nie, Yu Li, Ming Li

Department of Psychology: Faculty Publications

Serotonin 5-HT_2A and 5-HT_2C receptors play important yet distinctive roles in the regulation of rat maternal behavior. The present study investigated their neural substrates and explored the possible behavioral mechanisms (i.e., behavioral organization or maternal motivation). Sprague-Dawley postpartum females were microinjected with either a selective 5-HT_2A agonist (TCB-2, 0.4 or 4.0 μg/side) or a 5-HT_2C agonist (MK212, 2.5 or 5.0 μg/side) into the medial prefrontal cortex (mPFC) or ventral tegmental area (VTA). Ten and 60 min later, their maternal activities were observed in the home cage; and their motivational responses towards pups were examined in a …

A Systematic Review Of Genetic Influence On Psychological Resilience, Kosuke Niitsu, Michael J. Rice, Julia F. Houfek, Scott F. Stoltenberg, Kevin A. Kupzyk, Cecilia R. Barron

Department of Psychology: Faculty Publications

When exposed to adversity, some individuals are at an increased risk of posttraumatic stress disorder, experiencing persistent biopsychosocial disturbances, whereas others adapt well, described as resilience. Resilience is a complex biopsychosocial phenomenon conceptualized as adaptation to adversity influenced by an individual’s genetic variants, epistasis, epigenetics, and gene-by-environment interactions. Studies on psychological resilience have focused on behavioral and psychosocial variables with far less examination of the genetic contributions. The purpose of this review is to identify specific genetic variants contributing to the biological capacity for psychological resilience. PubMed and PsycINFO were searched using the following key words: psychological resilience AND genotype …

The Effect Of Maoa And Stress Sensitivity On Crime And Delinquency: A Replication Study, Christa C. Christ, Joseph A. Schwartz, Scott F. Stoltenberg, Jonathan R. Brauer, Jukka Savolainen

Department of Psychology: Faculty Publications

Across several meta-analyses, MAOA-uVNTR genotype has been associated with an increased risk for antisocial behavior among males who experienced early life adversity. Subsequently, early life stress and genetic susceptibility may have long-term effects on stress sensitivity later in life. In support of this assumption, a recent study found evidence, in two independent samples, for a three-way interaction effect (cG × E × E) such that proximate stress was found to moderate the interactive effect of MAOA-uVNTR and distal stress on crime and delinquency among males. In light of recent developments in cG × E research, we attempted to …

Alcohol Intoxication Moderates The Association Between A Polygenic Risk Score And Unprovoked Intimate Partner Aggression, Christa C. Christ, Laura E. Watkins, David Dilillo, Scott F. Stoltenberg

Department of Psychology: Faculty Publications

Despite evidence that genetic variation contributes to aggression, few studies have examined how genetic variation contributes to IPA specifically. In the current study, 69 couples from a Midwestern university completed self-report measures of IPA, childhood trauma exposure, and hazardous alcohol use, and were randomly assigned to consume either a placebo or alcohol beverage before participating in an analogue aggression task against their partner. Genetic risk (i.e., association with lower transcriptional efficiency) for aggression was measured with a polygenic risk score (PRS) created from four polymorphisms (HTR1B rs13212041, HTR2B rs6437000, 5-HTTLPR, and MAOA uVNTR). Among individuals with a low PRS, …

A Behavioral Mechanistic Investigation Of The Role Of 5-Ht1a Receptors In The Mediation Of Rat Maternal Behavior, Xiaonan Li, Xiaojing Ding, Ruiyong Wu, Leilei Chen, Jun Gao, Gang Hu, Ming Li

Department of Psychology: Faculty Publications

Previous work suggests that 5-HT_1A receptors play a special role in rodent maternal aggression, but not in other aspects of maternal care (e.g. pup retrieval and nest building). The present study re-assessed the basic effects of 5-HT_1A activation or blockade on various maternal responses in postpartum female rats. We also examined the possible behavioral mechanisms underlying the maternal effects of 5-HT_1A. Sprague–Dawley mother rats were injected with a 5-HT_1A agonist 8-OH-DPAT (0.1, 0.5 or 1.0 mg/kg, sc), a 5-HT_1A antagonist WAY-101405 (0.1, 0.5 or 1.0 mg/kg, sc) or 0.9% saline solution on postpartum days …

Ptsd, Alcohol Dependence, And Conduct Problems: Distinct Pathways Via Lability And Disinhibition, Jeffrey S. Simons, Raluca M. Simons, Carol O'Brien, Scott F. Stoltenberg, Jessica A. Keith, Jaime A. Hudson

Department of Psychology: Faculty Publications

This study tested the role of affect lability and disinhibition in mediating associations between PTSD symptoms and two forms of alcohol-related problems, dependence syndrome symptoms (e.g., impaired control over consumption) and conduct problems (e.g., assault, risk behaviors). Genotype at the serotonin transporter linked polymorphic region (5-HTTLPR) was hypothesized to moderate associations between traumatic stress and PTSD symptoms. In addition, the study tested whether childhood traumatic stress moderated associations between combat trauma and PTSD symptoms. Participants were 270 OIF/OEF/OND veterans. The hypothesized model was largely supported. Participants with the low expression alleles of 5-HTTLPR (S or L_G) exhibited stronger …

A Concept Analysis Of Resilience Integrating Genetics, Kosuke Niitsu, Julia F. Houfek, Cecilia R. Barron, Scott F. Stoltenberg, Kevin A. Kupzyk, Michael J. Rice

Department of Psychology: Faculty Publications

Although clinicians and researchers are interested in the phenomenon of resilience, there is no agreed-upon definition of resilience. Scientific evidence suggests that resilience is influenced by intrapersonal (e.g., personality traits) and environmental (e.g., social support) variables. A concept analysis was conducted to better understand the meaning of resilience. In this analysis, the antecedent of resilience was a potentially traumatic event; the defining attributes were ego-resiliency, emotion regulation, social support, and heredity; and the consequences were none to mild psychopathological symptoms and positive adaptation. This analysis can help nurses better understand resilience and its relationships …

A Systematic Review And Secondary Data Analysis Of The Interactions Between The Serotonin Transporter 5-Httlpr Polymorphism And Environmental And Psychological Factors In Eating Disorders, Vanja Rozenblat, Deborah Ong, Matthew Fuller-Tyszkiewicz, Kirsti Akkermann, David Collier, Rutger C. M. E. Engels, Fernando Fernandez-Aranda, Jaanus Harro, Judith R. Homberg, Andreas Karwautz, Evelyn Kiive, Kelly K. Klump, Sarah E. Racine, Jodie Richardson, Howard Steiger, Scott F. Stoltenberg, Tatjana Van Strien, Gudrun Wagner, Janet Treasure, Isabel Krug

Department of Psychology: Faculty Publications

Objectives: To summarize and synthesize the growing gene × environment (G × E) research investigating the promoter region of the serotonin transporter gene (5-HTTLPR) in the eating disorders (ED) field, and overcome the common limitation of low sample size, by undertaking a systematic review followed by a secondary data meta-analysis of studies identified by the review. Method: A systematic review of articles using PsycINFO, PubMed, and EMBASE was undertaken to identify studies investigating the interaction between 5-HTTLPR and an environmental or psychological factor, with an ED-related outcome variable. Seven studies were identified by the systematic review, with complete data sets …

An Exploratory High-Density Eeg Investigation Of The Misinformation Effect: Attentional And Recollective Differences Between True And False Perceptual Memories, John E. Kiat, Robert F. Belli

Department of Psychology: Faculty Publications

The misinformation effect, a phenomenon in which eyewitness memories are altered via exposure to post-event misinformation, is one of the most important paradigms used to investigate the reconstructive nature of human memory. The aim of this study was to use the misinformation effect paradigm to investigate differences in attentional and recollective processing between true and false event memories. Nineteen participants completed a variant of the misinformation paradigm in which recognition responses to true and misinformation based event details embedded within a narrative context, were investigated using high-density (256-channel) EEG with a 1-day delay between event exposure and test. Source monitoring …

Repeated Effects Of The Neurotensin Receptor Agonist Pd149163 In Three Animal Tests Of Antipsychotic Activity: Assessing For Tolerance And Cross-Tolerance To Clozapine, Shinnyi Chou, Collin Davis, Sean Jones, Ming Li

Department of Psychology: Faculty Publications

Neurotensin is an endogenous neuropeptide closely associated with the mesolimbic dopaminergic system and shown to possess antipsychotic-like effects. In particular, acute neurotensin receptor activation can inhibit conditioned avoidance response (CAR), attenuate phencyclidine (PCP)-induced prepulse inhibition (PPI) disruptions, and reverse PCP-induced hyperlocomotion. However, few studies have examined the long term effects of repeated neurotensin receptor activation and results are inconsistent. Since clinical administration of antipsychotic therapy often requires a prolonged treatment schedule, here we assessed the effects of repeated activation of neurotensin receptors using an NTS1 receptor selective agonist, PD149163, in 3 behavioral tests of antipsychotic activity. We also investigated whether …

Asenapine Sensitization From Adolescence To Adulthood And Its Potential Molecular Basis, Qing Shu, Rongyin Qin, Yingzhu Chen, Gang Hu, Ming Li

Department of Psychology: Faculty Publications

Asenapine is a new antipsychotic drug that induces a long-lasting behavioral sensitization in adult rats. The present study investigated the developmental impacts of adolescent asenapine treatment on drug sensitivity and on 3 proteins implicated in the action of antipsychotic drugs (i.e. Brainderived neurotrophic factor (BDNF), dopamine D₂ receptor, and ΔFosB) in adulthood. Male adolescent Sprague-Dawley rats (postnatal days, P 43-48) were first treated with asenapine (0.05, 0.10 or 0.20 mg/kg, sc) and tested in the conditioned avoidance or PCP (2.0 mg/kg, sc)-induced hyperlocomotion tasks for 5 days. After they became adults (∼P 76), asenapine sensitization was assessed in a …

Effect Of Environmental Cues On Behavioral Efficacy Of Haloperidol, Olanzapine And Clozapine In Rats, Tao Sun, Xinfeng Liu, Ming Li

Department of Psychology: Faculty Publications

Previous studies have reported that context can powerfully modulate the inhibitory effect of an antipsychotic drug on phencyclidine (PCP)-induced hyperlocomotion (a behavioral test used to evaluate putative antipsychotic drugs). The present study investigated the experimental conditions under which environmental stimuli exert their influence through associative conditioning processes. Experiment 1 examined the extent to which prior antipsychotic treatment in the home cages affected a drug’s ability to inhibit PCP-induced hyperlocomotion in a novel motor activity test apparatus. Five days of repeated haloperidol (0.05 mg/kg, sc) and olanzapine (2.0 mg/kg, sc) treatment in the home cages still potentiated their inhibition of PCP-induced …

Evolutionary Pressures On Primate Intertemporal Choice, Jeffrey R. Stevens

Department of Psychology: Faculty Publications

From finding food to choosing mates, animals must make intertemporal choices that involve fitness benefits available at different times. Species vary dramatically in their willingness to wait for delayed rewards. Why does this variation across species exist? An adaptive approach to intertemporal choice suggests that time preferences should reflect the temporal problems faced in a species' environment. Here, I use phylogenetic regression to test whether allometric factors (relating to body size), relative brain size, and social group size predict how long 13 primate species will wait in laboratory intertemporal choice tasks. Controlling for phylogeny, a composite allometric factor that includes …

Effects Of 5-Hydroxytryptamine 2c Receptor Agonist Mk212 And 2a Receptor Antagonist Mdl100907 On Maternal Behavior In Postpartum Female Rats, Weihai Chen, Qi Zhang, Wenxin Su, Yu Yang, Jing Qiao, Nan Sui, Ming Li

Department of Psychology: Faculty Publications

Maternal behavior in rats is a highly motivated and well-organized social behavior. Given the known roles of serotonin (5-HT) in emotion, motivation, social behavior, and major depression – and its known interaction with dopamine – it is likely that serotonin also plays a crucial role in this behavior. So far, there are surprisingly few studies focusing on 5-HT in maternal behavior, except for maternal aggression. In the present study,we examined the effects of 5-HT_2C receptor agonism and 5-HT_2A receptor antagonism on maternal behavior in postpartum female rats.We hypothesized that activation of 5-HT_2C receptors and blockade of 5-HT …

Iptakalim Attenuates Self-Administration And Acquired Goal-Tracking Behavior Controlled By Nicotine, S. Charntikov, N. Swalve, Steven T. Pittenger, K. Fink, S. Schepers, G. C. Hadlock, A. E. Fleckenstein, G. Hu, Ming Li, Rick A. Bevins

Department of Psychology: Faculty Publications

Iptakalim is an ATP-sensitive potassium channel opener, as well as an a4b2-containing nicotinic acetylcholine receptor (nAChR) antagonist. Pretreatment with iptakalim diminishes nicotine-induced dopamine (DA) and glutamate release in the nucleus accumbens. This neuropharmacological profile suggests that iptakalim may be useful for treatment of nicotine dependence. Thus, we examined the effects of iptakalim in two preclinical models. First, the impact of iptakalim on the interoceptive stimulus effect of nicotine was evaluated by training rats in a discriminated goal-tracking task that included intermixed nicotine (0.4 mg/kg, SC) and saline sessions. Sucrose was intermittently presented in a responseindependent manner only on nicotine sessions. …

Repeated Asenapine Treatment Produces A Sensitization Effect In Two Preclinical Tests Of Antipsychotic Activity, Rongyin Qin, Yingzhu Chen, Ming Li

Department of Psychology: Faculty Publications

Among several commonly used atypical antipsychotic drugs, olanzapine and risperidone cause a sensitization effect in the conditioned avoidance response (CAR) and phencyclidine (PCP)- induced hyperlocomotion paradigms – two well established animal tests of antipsychotic drugs, whereas clozapine causes a tolerance effect. Asenapine is a novel antipsychotic drug recently approved for the treatment of schizophrenia and manic disorders. It shares several receptor binding sites and behavioral features with other atypical antipsychotic drugs. However, it is not clear what type of repeated effect (sensitization or tolerance) asenapine would induce, and whether such an effect is transferrable to other atypicals. In this study, …

Afraid To Help: Social Anxiety Partially Mediates The Association Between 5-Httlpr Triallelic Genotype And Prosocial Behavior, Scott F. Stoltenberg, Christa C. Christ, Gustavo Carlo

Department of Psychology: Faculty Publications

There is growing evidence that the serotonin system influences prosocial behavior. We examined whether anxiety mediated the association between variation in the serotonin transporter gene regulatory region (5-HTTLPR) and prosocial behavior. We collected self-reported tendencies to avoid certain situations and history of helping others using standard instruments and buccal cells for standard 5-HTTLPR genotyping from 398 undergraduate students. Triallelic 5-HTTLPR genotype was significantly associated with prosocial behavior and the effect was partially mediated by social anxiety, such that those carrying the S′ allele reported higher levels of social avoidance and lower rates of helping others. These results are consistent with …

Impulsiveness Mediates The Association Between Gabra2 Snps And Lifetime Alcohol Problems, S. Villafuerte, V. Strumba, S. F. Stoltenberg, R. A. Zucker, M. Burmeister

Department of Psychology: Faculty Publications

Genetic variants in GABRA2 have previously been shown to be associated with alcohol measures, electroencephalography (EEG) β waves and impulsiveness-related traits. Impulsiveness is a behavioral risk factor for alcohol and other substance abuse. Here, we tested association between 11 variants in GABRA2 with NEO-impulsiveness and problem drinking. Our sample of 295 unrelated adult subjects was from a community of families with at least one male with DSM-IV alcohol use diagnosis, and from a socioeconomically comparable control group. Ten GABRA2 SNPs (single-nucleotide polymorphisms) were associated with the NEO-impulsiveness (P < 0.03). The alleles associated with higher impulsiveness correspond to the minor alleles identified in previous alcohol dependence studies. All ten SNPs are in linkage disequilibrium (LD) with each other and represent one effect on impulsiveness. Four SNPs and the corresponding haplotype from intron 3 to intron 4 were also associated with Lifetime Alcohol Problems Score (LAPS, P < 0.03) (not corrected for multiple testing). Impulsiveness partially mediates (22.6% average) this relation between GABRA2 and LAPS. Our results suggest that GABRA2 variation in …

Olanzapine Sensitization And Clozapine Tolerance: From Adolescence To Adulthood In The Conditioned Avoidance Response Model, Jing Qiao, Hong Li, Ming Li

Department of Psychology: Faculty Publications

Disruption of conditioned avoidance response (CAR) in rodents is one trademark feature of many antipsychotic drugs. In adult rats, repeated olanzapine (OLZ) treatment causes an enhanced disruption of avoidance response (sensitization), whereas repeated clozapine (CLZ) treatment causes a decreased disruption (tolerance). The present study addressed (1) whether OLZ sensitization and CLZ tolerance can be induced in adolescent rats, and (2) the extent to which OLZ sensitization and CLZ tolerance induced in adolescence persists into adulthood. Male adolescent Sprague–Dawley rats (approximate postnatal days (BP) 43–47) were first treated with OLZ (1.0 or 2.0 mg/kg, subcutaneously (sc)) or CLZ (10 or 20 …

Spectrum Of Acute Clinical Characteristics Of Diagnosed Concussions In College Athletes Wearing Instrumented Helmets, Ann-Christine Duhaime,, Jonathan G. Beckwith, Arthur C. Maerlender, Thomas W. Mcallister, Joseph J. Crisco, Stefan M. Duma, P. Gunnar Brolinson, Steven Rowson, Laura A. Flashman, Jeffrey J. Chu, Richard M. Greenwald

Department of Psychology: Faculty Publications

Object. Concussive head injuries have received much attention in the medical and public arenas, as concerns have been raised about the potential shortand long-term consequences of injuries sustained in sports and other activities. While many student athletes have required evaluation after concussion, the exact definition of concussion has varied among disciplines and over time. The authors used data gathered as part of a multiinstitutional longitudinal study of the biomechanics of head impacts in helmeted collegiate athletes to characterize what signs, symptoms, and clinical histories were used to designate players as having sustained concussions.

Methods. Players on 3 college …

Serotonin System Gene Polymorphisms Are Associated With Impulsivity In A Context Dependent Manner, Scott F. Stoltenberg, Christa C. Christ, Krista B. Highland

Department of Psychology: Faculty Publications

Impulsivity is a risk factor for adverse outcomes and characterizes several psychiatric disorders and risk for suicide. There is strong evidence that genetic variation influences individual differences in impulsivity, but the details are not yet understood. There is growing interest in better understanding the context dependency of genetic effects that is reflected in studies examining gender specificity, gene × environment interaction and epistasis (gene-gene interaction). In a cross-sectional study we examined whether polymorphisms in six serotonin system candidate genes and the experience of early life trauma (age 0–12) were associated with individual differences in impulsivity in a nonclinical sample of …

Conditioned Response Evoked By Nicotine Conditioned Stimulus Preferentially Induces C-Fos Expression In Medial Regions Of Caudate-Putamen, Sergios Charntikov, Matthew E. Tracy, Changjiu Zhao, Ming Li, Rick A. Bevins

Department of Psychology: Faculty Publications

Nicotine has both unconditioned and conditioned stimulus properties. Conditioned stimulus properties of nicotine may contribute to the tenacity of nicotine addiction. The purpose of this experiment was to use neurohistochemical analysis of rapidly developing c-Fos protein to elucidate neurobiological loci involved in the processing of nicotine as an interoceptive conditioned stimulus (CS). Rats were injected (SC) in an intermixed fashion with saline or nicotine (16 sessions of each) and placed in conditioning chambers where they were given one of the three conditions depending on group assignment: (a) nicotine paired 100% of the time with intermittent access to sucrose (nicotine-CS condition), …

Iptakalim Preferentially Decreases Nicotine-Induced Hyperlocomotion In Phencyclidine-Sensitized Rats: A Potential Dual Action Against Nicotine Addiction And Psychosis, Nick Volf, Gang Hu, Ming Li

Department of Psychology: Faculty Publications

Objective: Iptakalim is a putative ATP-sensitive potassium (KATP) channel opener. It is also a novel nicotinic acetylcholine receptor (nAChR) blocker and can antagonize nicotine-induced increase in dopamine release in the nucleus accumbens. Our recent work also shows that iptakalim exhibits a clozapine-like atypical antipsychotic profile, indicating that iptakalim may possess a dual action against nicotine addiction and schizophrenia.

Methods: The present study examined the potential therapeutic effects of iptakalim on nicotine use in schizophrenia. We created an animal model of comorbidity of nicotine addiction and schizophrenia by injecting male Sprague-Dawley rats with nicotine (0.40 mg/kg, subcutaneously［sc］) or saline, in combination …

Gender Moderates The Association Between 5-Httlpr And Decision-Making Under Ambiguity But Not Under Risk, Scott F. Stoltenberg, Joanna M. Vandever

Department of Psychology: Faculty Publications

Decisions made under ambiguity may involve a different genetic architecture than those made under risk. Because gender moderates the effect of genetic polymorphisms on serotonin function and because there are gender differences in decision-making, the present study examined potential gender moderation of associations between polymorphisms in important serotonin system candidate genes (serotonin transporter [SLC6A4] and tryptophan hydroxylase-2 [TPH2]) and performance on a decision-making task (Iowa Gambling Task, IGT) in healthy, adults (N = 188; 62% women). Subjects were genotyped for the well-studied SLC6A4 promoter variant 5-HTTLPR and a TPH2 single nucleotide polymorphism in intron-8 (rs1386438). Genotype at rs1386438was not …

Recent Progress In Psychiatric Genetics—Some Hope But No Hype, Scott F. Stoltenberg, Margit Burmeister

Department of Psychology: Faculty Publications

The reputation of the field of psychiatric genetics has recently become tarnished in the view of many human geneticists. Too many linked loci were claimed and withdrawn, too many association studies published and not confirmed, and, more recently, too many new and different chromosomal regions have been implicated for the same disorder. Here, we summarize recent trends, focusing on research that moves away from traditional linkage studies. Some promising strategies include psychopharmacogenetics and consideration of endophenotypes such as neurophysiological and behavioral markers in addition to the clinical diagnosis. Utilization of rapid and automated methods for scoring genetic variants in large-scale …

Potential Associations Among Genetic Markers In The Serotonergic System And The Antisocial Alcoholism Subtype, E. M. Hill, S. F. Stoltenberg, M. Burmeister, M. Closser, R. A. Zucker

Department of Psychology: Faculty Publications

Alcoholism is transmitted in families. The complexity and heterogeneity of this disorder has made it difficult to identify specific genetic correlates. One design with the potential to do so is the family-based association study, in which the frequencies of genetic polymorphisms are compared between affected and nonaffected members. Reduced central serotonin neurotransmission is associated with features of an antisocial subtype of alcoholism, although a primary deficit has not been traced to a particular component. Genetic markers related to the serotonergic system have been identified, located, and cloned. If associations can be discovered, the development process for pharmacotherapy could be facilitated. …

Coming To Terms With Heritability, Scott F. Stoltenberg

Department of Psychology: Faculty Publications

The complex mechanisms of heredity are little appreciated by nonspecialists, in some measure, because of misunderstandings that are perpetuated when words used for technical terms have other, more widely understood, folk meanings. When a word has both technical and folk meanings, it is the responsibility of the specialist to avoid promoting confusion by either using extremely cautious and precise language when using the term or, in cases when confusion is inevitable, abandoning the term in favor of one without a widely understood folk meaning. The study of heredity is beset by such confusion, and the term heritability appears to be …

Y-Chromosome Effects On Drosophila Geotaxis Interact With Genetic Or Cytoplasmic Background, Scott F. Stoltenberg, Jerry Hirsch

Department of Psychology: Faculty Publications

Previously, all of the major fruit fly, Drosophila melanogaster, chromosomes (I, II, and III) have been shown to be associated with geotaxis, but the Y chromosome has not. Using two methods (back-crossing and chromosome substitution), Y chromosomes from lines that have evolved stable, extreme expressions of geotaxis were placed into different genetic and cytoplasmic backgrounds to test the resulting males for geotaxis. The results of the back-crossing do not support the interpretation of Y-chromosome effects on geotaxis. These tests do not have sufficient statistical power, however, to detect small genetic effects. In the chromosome substitution experiment, the geotaxis-line Y …

A Gene Correlate Of Geotaxis Near Adh (2-50.1) In Drosophila Melanogaster, Scott F. Stoltenberg, Jerry Hirsch

Department of Psychology: Faculty Publications

As part of a long-term study (38+ years) to identify genetic correlates of geotaxis in Drosophila melanogaster, the investigators report the results of allozyme-level analyses of 2 lines derived from hybridizing high- and low-selected lines that have evolved stable, extreme expressions of geotaxis. Allelic variation at Adh was associated with geotactic performance in 1 hybrid-derived line, but not in another, after 66 free-mating generations beyond the F₂ generation. A second-chromosome gene correlate of geotaxis may lie within 1 map unit of Adh. Population genetic analyses suggest that there were different selection pressures on the hybrid-derived lines and …