Psychology Commons^™

Circuits Underlying Serotonin Mediated Sex Differences In Fear Learning, Rebecca Ravenelle

Dissertations, Theses, and Capstone Projects

Post-traumatic stress disorder (PTSD) is a trauma-related disorder characterized by intense fearful memory formation. Women are twice as likely as men to develop PTSD, indicating there may be sex differences in the underlying neural circuits. Given that serotonin (5-HT) dysfunction is implicated in PTSD, and 5-HT modulates fear learning, we investigated whether there are sex differences in the modulation of fear learning by 5-HT. We administered the selective serotonin reuptake inhibitor (SSRI) citalopram (20mg/kg or 10m/kg, i.p.) once to male and female mice prior to auditory fear conditioning and tested the effects on fear memory the next day. We found …

The Development And Evaluation Of Novel Da Transport Inhibitors And Their Effects On Effort-Related Motivation: A Review, Mukund Desibhatla

Honors Scholar Theses

Depression is a debilitating disorder that can cause motivational deficits such as psychomotor retardation, anergia, apathy, and fatigue. Recent research indicates that these motivational deficits, and potential pathways of therapeutic intervention, can be studied in animal models involving rats and mice. Treatments with the VMAT-2 inhibitor tetrabenazine (TBZ) and cytokine interleukin-1ß (IL-1ß) can create a low-effort bias and impair effort-related motivation (Nunes et al. 2013, 2014). A number of high-affinity DA transport inhibitors such as d-amphetamine, methylphenidate, and cocaine can restore extracellular DA, albeit with the cost of undesirable effects such as high abuse liability. These observations have led researchers …

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 …

Effort-Related Motivational Dysfunctions: Behavioral And Neurochemical Studies Of The Wistar-Kyoto Rat Model Of Depression, Brendan Abbott

Masters Theses

Depression and related disorders are characterized by motivational dysfunctions, including deficits in behavioral activation and exertion of effort. Animal models of relevance to depression represent a critical starting point in elucidating the neurobiological mechanisms underlying motivational dysfunctions. The present study explored the use of the Wistar-Kyoto (WKY) animal model of depression to examine effort-related functions as measured by voluntary wheel running and performance on a mixed fixed ratio 5/progressive ratio (FR5/PR) operant task. Given the known link between activational aspects of motivation and the mesocorticolimbic dopamine (DA) system, the behavioral effects of d-amphetamine (0.5 and 1.0 mg/kg, IP), a psychostimulant …

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 …

Discriminative Stimulus Properties Of 1.25 Mg/Kg Clozapine In Rats: Mediation By Serotonin 5-Ht2 And Dopamine D4 Receptors, Adam J. Prus, Laura Wise, Alan L. Pehrson, Scott D. Philibin, Benny Bang-Andersen, Jørn Arnt, Joseph H. Porter

Journal Articles

The atypical antipsychotic drug clozapine remains one of most effective treatments for schizophrenia, given a lack of extrapyramidal side effects, improvements in negative symptoms, cognitive impairment, and in symptoms in treatment-resistant schizophrenia. The adverse effects of clozapine, including agranulocytosis, make finding a safe clozapine-like a drug a goal for drug developers. The drug dis- crimination paradigm is a model of interoceptive stimulus that has been used in an effort to screen experimental drugs for clozapine-like atypical antipsychotic effects. The present study was conducted to elucidate the receptor-mediated stimulus properties that form this clozapine discriminative cue by testing selective receptor ligands …

Associations Between Hypothalamic-Pituitary-Adrenal Axis System Gene Variants And Cortisol Reactivity In Preschoolers: Main Effects And Gene-Environment Interactions, Haroon I. Sheikh

Electronic Thesis and Dissertation Repository

Exposure to stressful events during early development has consistently been shown to produce long lasting effects on the hypothalamic-pituitary-adrenal (HPA) axis, which may increase vulnerability to mood and anxiety disorders. Recently reported genetic association studies indicate that these disorders may be influenced, in part, by gene-environment interactions (GxE) involving polymorphisms within the corticotrophin-releasing hormone and monoaminergic system genes. However, little is known about how genetic variants and life stress work to shape children’s neuroendocrine reactivity and emerging symptoms. Therefore, the aim of this thesis is to examine main effects of candidate genes and GxE on the neuroendocrine stress response and …

Day-Night Differences In Neural Activation In Histaminergic And Serotonergic Areas With Putative Projections To The Cerebrospinal Fluid In A Diurnal Brain, Alexandra Castillo-Ruiz, Andrew J. Gall, Laura Smale, Antonio A. Nunez

Faculty Publications

In nocturnal rodents, brain areas that promote wakefulness have a circadian pattern of neural activation that mirrors the sleep/wake cycle, with more neural activation during the active phase than during the rest phase. To investigate whether differences in temporal patterns of neural activity in wake-promoting regions contribute to differences in daily patterns of wakefulness between nocturnal and diurnal species, we assessed Fos expression patterns in the tuberomammillary (TMM), supramammillary (SUM), and raphe nuclei of male grass rats maintained in a 12:12 h light-dark cycle. Day-night profiles of Fos expression were observed in the ventral and dorsal TMM, in the SUM, …

Serotonin, Motivation, And Playfulness In The Juvenile Rat, Stephen M. Siviy, Loren M. Deron, Chelsea R. Kasten

Psychology Faculty Publications

The effects of the selective 5HT1A agonist 8-OH-DPAT were assessed on the play behavior of juvenile rats. When both rats of the test pair were comparably motivated to play, the only significant effect of 8-OH-DPAT was for play to be reduced at higher doses. When there was a baseline asymmetry in playful solicitation due to a differential motivation to play and only one rat of the pair was treated, low doses of 8-OH-DPAT resulted in a collapse of asymmetry in playful solicitations. It did not matter whether the rat that was treated initially accounted for more nape contacts or fewer …

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 …

Mechanism Of Triazolo-Benzodiazepine And Benzodiazepine Action In Anxiety And Depression: Behavioral Studies With Concomitant In Vivo Ca1 Hippocampal Norepinephrine And Serotonin Release Detection In The Behaving Animal, Patricia A. Broderick, Omotola Hope, Pierrot Jeannot

Publications and Research

1. Real time, in vivo microvoltammetric studies were performed, using miniature carbon-based sensors, to concurrently detect norepinephrine (NE) release and serotonin (5-HT) release, in 2 separate electrochemical signals, within CA₁ region of hippocampus in the freely moving and behaving, male, Sprague Dawley laboratory rat.

2. Concurrently, four parameters of open-field Behavior I.E. Ambulations, Rearing, Fine Movements and Central Ambulatory behavior (a measure of anxiety reduction behavior), were assayed by infrared photobeam detection.

3. Time course studies showed that the mechanism of action of the triazolobenzodiazepine (TBZD), adinazolam, (Deracyn®) is dramatically different from that of the classical benzodiazepine (BZD), diazepam …