Biological Psychology Commons^™

Local Field Potentials In The Male Rat Nucleus Accumbens During Effort-Based Behavior, Celine Aliko, John Salamone, Alev Ecevitoglu

Honors Scholar Theses

Major depression is a devastating disorder that consists of multiple symptoms such as low mood and motivational dysfunction. It has been shown that motivational dysfunction can be studied in animal models by using effort-based choice paradigms, which vary in their response requirements. It has been reported that dopamine depletion in the nucleus accumbens decreases ratio-scheduled lever-pressing in a manner related to the size of the ratio requirement. One dopamine depleting agent is tetrabenazine (TBZ), which has been shown to decrease lever-pressing and induce low-effort bias. The current study aims to investigate behavioral and electrophysiological changes that occur with animals performing …

Identifying Neuron Clusters Controlling Movement Vigor, Jay A. Strabinick

Cal Poly Humboldt theses and projects

Parkinson’s disease (PD) is a neurodegenerative disease that progressively decreases dopaminergic function. Lower amounts of dopamine may cause an innate motivational shift that decreases movement vigor when performing difficult tasks. In PD patients, bradykinesia, the slowing of movement, is characteristic of this decrease in vigor. The movement vigor hypothesis proposes that dopamine neurons modulate performance aspects of movement, like speed and persistence. This paper proposes a series experiments utilizing neuron recording techniques in zebrafish that would test the movement vigor hypothesis by determining whether in fact there is a distinct group of dopamine neurons that modulate movement vigor. Core elements …

Behavioral, Endocrine, And Neural Responses To Stress In Postpartum And Nulliparous Rats : Potential Mechanisms Of Postpartum Stress Resilience, Joanna Medina

Legacy Theses & Dissertations (2009 - 2024)

Major depressive disorder is one of the most pervasive psychiatric illnesses in the United States. Women are at greater risk for developing depression, particularly during their childbearing years. Approximately 17% of new mothers develop postpartum depression within 4 weeks after parturition. The risk for postpartum depression is even greater in women who do not breastfeed or stop breastfeeding early. Major depressive disorder and postpartum depression share the same symptomology and common etiological bases. Dysregulated stress responses, dopamine activity, and neuroinflammation are recognized mechanisms for depression. The transition to motherhood encompasses physiological and behavioral adaptations in the brain essential for ensuring …

Assessment Of Dopaminergic And Serotonergic Receptor Antagonists In Male Rats Trained To Discriminate 4-Methylmethcathinone (Mephedrone), Rachel L. Burroughs

Masters Theses

Preclinical drug discrimination studies of the synthetic cathinone, 4-methylmethcathinone (mephedrone) have demonstrated its effects are comparable to those of other popular psychostimulant drugs. Few studies have directly examined the contribution of specific neurotransmitter receptors to mephedrone’s discriminative stimulus effects. The present study investigated the role of dopamine and serotonin receptors in these effects. Eight adult male Sprague-Dawley rats were trained to discriminate 3.0 mg/kg mephedrone from saline. After dose-response curves were determined with mephedrone (0.375-3.0 mg/kg), a series of stimulus antagonism tests were conducted with dopamine antagonists (Sch 23390, haloperidol) and serotonin antagonists (WAY 100,635, MDL 100,907, pirenperone) administered as …

The Role Of Dopamine In Decision Making Processes In Drosophila Melanogaster, Michelle C. Bowers

Undergraduate Honors Theses

Understanding the neural processes that mediate decision making is a relatively new field of investigation in the scientific community. With the ultimate goal of understanding how humans decide between one path and another, simpler models such as Drosophila Melanogaster, the common fruit fly, are often utilized as a way of determining the neural circuits involved in these decision-making processes. One of the most important decisions flies make is the decision of where to lay their eggs (oviposit). Choosing the proper substrate upon which to lay eggs is a crucial decision that can ultimately impact their fecundity. This paper investigates the …

Structure And Function Of Dopamine In The Inner Ear And Auditory Efferent System Of A Vocal Fish, Jonathan T. Perelmuter

Dissertations, Theses, and Capstone Projects

The neuromodulator dopamine is considered essential for coordinating the internal motivational state of an organism with appropriate behavioral responses to stimuli in the external environment. This could be accomplished by modifying the function of neural circuits involved in sensory processing such that they are “tuned in” and optimally sensitive to important stimuli during critical time windows. While dopamine modulation of auditory processing has been studied in the central nervous system, neuromodulation can also occur outside the brain, in the inner ear. The majority of investigations of dopamine in the ear are conducted using rodents and focus on its role in …

Murine Genetic Variance In Sugar And Fat-Conditioned Flavor Preferences: Roles Of Dopamine, Opioid And Nmda Receptors And Nutritive Sensing, Tamar T. Kraft

Dissertations, Theses, and Capstone Projects

As obesity and diabetes have emerged as a severe public health crisis, understanding the mechanisms underlying the consumption of sugars and fats has become a topic of vigorous study. From a biological standpoint, genetic dispositions, neurochemical and hormonal influences, and predetermined orosensory and postingestive signals that modulate the hunger and satiety process may govern physiological aspects of the obesity puzzle. In addition to an innate appetite and attraction for simple carbohydrates and fats, learning plays an important role in modulating preferences for sugar- and fat-rich foods in rodents, including inbred mouse strains. Marked genetic variance has been observed among murine …

The Effect Of Dopamine Blockade On Sensorimotor Gating In Social Phenotypes Of The African Cichlid Fish Astatotilapia Burtoni, Raymond A. Turco

Theses and Dissertations

We asked if blocking dopamine could improve implicit sensory gating deficits in a socially-defeated fish of a naturally-agonistic species. This study investigated the effects of dopamine D2R receptor antagonist metoclopramide on sensorimotor gating using a prepulse inhibition (PPI) paradigm in social phenotypes of male A. burtoni African cichlid fish.

Examining The Associative Learning And Accumbal Dopaminergic Mechanisms Of Caffeine Reinforcement, Curtis Bradley

Electronic Theses and Dissertations

Caffeine is the most consumed psychoactive substance in the world, and most caffeine consumption in coffee and energy drinks is intended to produce a psychoactive effect. However, caffeine is not a primary reinforcer in preclinical paradigms – non-human species do not reliably take the drug to produce a psychoactive effect. However, caffeine is a ‘reinforcement enhancer’ in preclinical models; the effects of caffeine increase the motivation to obtain other non-drug reinforcers. The overall goal of this project was to determine if these reinforcement enhancing effects of caffeine could promote caffeine self-administration and to subsequently investigate the behavioral and neurochemical underpinnings …

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 …

Effort-Related Decision Making In Comt Variant Mice: Pharmacological Studies And Genetic Susceptibility To Motivational Dysfunction, Suzanne Cayer

Honors Scholar Theses

Effort-related decision making tasks in animals can model motivational symptoms in humans, which are a set of symptoms spanning a multitude of neuropsychiatric disorders, such as major depressive disorder and the negative symptoms of schizophrenia. The present studies aimed to evaluate the effort-related effects of the Val158Met polymorphism of human catechol-methyltransferase (COMT), by testing mice carrying either the human COMT Val (n=8) or Met allele (n=8) with Wild-Type control mice (n=15) by using concurrent FR2 and FR4/pellet choice tasks in a touchscreen operant conditioning apparatus. The Val158Met polymorphism has been repeatedly associated with neuropsychiatric disorders, and the Val allele has …

Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy

University of New Orleans Theses and Dissertations

The model of basal ganglia function proposed by Albin, Young and Penney (1989) describes two anatomically independent motor pathways, the direct and indirect. However, under normal conditions striatal dopamine (DA) is required for the expression of motor behavior, and DAergic control of the two pathways (via D1 and D2 receptors, respectively) is dependent on co-activation. We tested for a possible breakdown of D1/D2 synergism using transgenic R6/1 mice bearing the human huntingtin allele (Htt). Motor stereotypy, observed prior to the onset of HD-related symptoms, was rated on a 5-point scale following activation of: A) D1 receptors alone, B) D2 receptors …

The Nucleus Accumbens Core Dopamine D1 And Glutamate Ampa/Nmda Receptors Play A Transient Role In The Performance Of Pavlovian Approach Behavior, Veronica Dobrovitsky

Dissertations, Theses, and Capstone Projects

The role of the nucleus accumbens core (NAc core) continues to be redefined with newly acquired data on neurochemical mechanisms mediating the learning and performance of behavior. Previous empirical data showed that dopamine transmission at the D1 receptor (D1R) plays a transient role in the expression of learned Pavlovian approach behavior. Here we show that, prior to overtraining, dopamine activity at D1Rs specifically within the NAc core is critical for the performance of approach behavior elicited by the recently-acquired reward-paired cue. Blockade of D1Rs in the NAc core, but not the dorsomedial striatum or NAc shell, disrupted approach responses during …

Are Caffeine’S Effects On Neuronal Calcium Levels Due To The Caffeine Metabolite, Paraxanthine?, Kendra Jean Hartsuyker

Cal Poly Humboldt theses and projects

Caffeine has diverse effects on neurons including, potentially, protection against Parkinson’s-related neurodegeneration. Caffeine may protect neurons from damage by limiting mitochondrial membrane permeability through a calcium-dependent mechanism. This study was a first step investigating calcium’s role in caffeine neuroprotection in vivo using zebrafish larvae. Elavl3:GCaMP6s zebrafish, which express a genetically encoded fluorescent calcium indicator protein in most CNS neurons, received caffeine (0, 50, 125, 250 µM, bath applied) in an ascending dose series during fluorescence calcium imaging of a central catecholaminergic nucleus (a proposed zebrafish homolog of the locus coeruleus, a structure affected in Parkinson’s disease). Parallel experiments tested effects …

Cannabis Use Frequency And Mood On Creativity, Caitlin Clark

Cal Poly Humboldt theses and projects

This study examines the relationship between cannabis use (infrequent, moderate, and heavy use) and one’s mood (neutral, positive, and negative) on creativity. Folk ideas of creativity and the relationships between cannabis use and mood may not reflect the real relationship between these factors (e.g. regarding cannabis use, it is perceived to be linked with higher rates of creativity; regarding mood, negative states [i.e. tortured artist] are thought to fuel creativity). Although both cannabis use and mood have been found to influence creativity independently, the current study is unique in its aims to identify whether cannabis use and mood interact to …

Effects Of Optogenetic Activation And Pharmacological Modulation Of Dopamine Neurons, Remington J. Rice

All NMU Master's Theses

This study explored the use of optogenetic tools to better understand treatments used for schizophrenia. The “positive” symptoms (e.g., hallucinations, paranoia, etc.) of schizophrenia may come from overexpression of dopamine in mesolimbic dopamine neurons. Positive symptoms can be produced in healthy volunteers treated with amphetamine, a psychostimulant drug and dopamine releaser. Conversely, antipsychotic drugs may reduce positive symptoms by blocking dopamine receptors. This study used optogenetics to explore how drugs that alter neurotransmission, might alter behaviors occurring from activation of mesolimbic dopamine (DA) neurons in the ventral tegmental area (VTA). Light-induced activation of DA neurons in the VTA in male …

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 …

Individual Differences In The Dopaminergic Reward System: The Effect Of Genetic Risk On Neural Reward Sensitivity And Risky Choice, Heather E. Soder

USF Tampa Graduate Theses and Dissertations

When making decisions, individuals evaluate several possible outcomes of their choice; however, some display heightened reward sensitivity, despite the potential for future negative consequences, which can lead one to make risky choices. Rewards are processed in the mesolimbic dopamine reward system, and this system is in part modulated by genetic polymorphisms that are associated with dopamine transmission. The current study tested if genetic polymorphisms that are associated with enhanced dopamine neurotransmission will be more neurally reward sensitive, score higher on self-reported impulsivity, and make riskier choices. In a sample of 85 participants, five genetic polymorphisms were genotyped and used to …

Genetic Moderation Of Phenotypic And Neural Indicators Of Peer Influenced Risk-Taking Behavior: An Experimental Investigation, Troy Alan Webber

USF Tampa Graduate Theses and Dissertations

Risk-taking behavior (RTB) is defined as behavior involving the probability of reward with concurrent probability of some negative outcome. Peer influence is among the most robust predictors of RTB, such that greater peer influence, particularly deviant or delinquent peer influence, is associated with increased RTB. Evidence suggests that those with genetic predispositions for RTB may also be more susceptible to peer influence as a function of genotype. Given that genetic polymorphisms within the dopaminergic system have evidenced associations with various forms of RTB and delinquent peer affiliation, it is possible that these genes may interact with peer influence to predict …

Cocaine-Induced Behavioral Sensitization And Conditioned Place Preference In Japanese Quail (Coturnix Japonica): A Focus On Sex Differences And Dopaminergic Mechanisms, Karin E. Gill

Theses and Dissertations--Psychology

Research has indicated that gonadal hormones may mediate behavioral and biological responses to cocaine. Estrogen, in particular, has been shown to increase behavioral responding to cocaine in female rats relative to male rats. The use of Japanese quail may add to our knowledge of sex differences in drug abuse because of their advanced visual system and the ability to control their gonadal hormones via alterations in photoperiod. In three experiments, cocaine-induced behaviors were examined using this avian model.

In Experiment 1, I investigated the potential sex differences in cocaine-induced locomotor activity between male and female Japanese quail and I examined …

The Influence Of Dopamine On The Magnitude And Duration Of The Placebo Effect, Steve T. Brewer

University of New Orleans Theses and Dissertations

A placebo effect is a real and beneficial psychobiological phenomenon following the administration of a substance or procedure that has no inherent power to produce an effect. Nocebo effects, on the other hand are genuine and detrimental psychobiological phenomenon following the administration of and inert substance or procedure. These effects have been extensively studied but are not well understood. Central to the development of a placebo effect is the anticipation of benefit or the anticipation of harm. Indeed, expectancy and conditioning are thought to be the two primary mechanisms involved in the acquisition of the placebo effect. The neurotransmitter Dopamine …

The Neurobehavioral Consequences Of Gestational And Chronic Atrazine Exposure In Male And Female Sprague Dawley Rats, Jennifer L. Walters

Dissertations

The adverse health risks of exposure to the herbicide, atrazine, in humans are not fully understood. Although numerous studies have demonstrated atrazine to be an endocrine disrupter, the neurobehavioral consequences of atrazine exposure have not been thoroughly examined. The aim of this study was to investigate the effects of environmentally-relevant levels

of gestational followed by continued chronic atrazine exposure on motor function, learning and memory, anxiety, and striatal dopamine content in rodents. Pregnant Sprague Dawley rats were treated by gavage with 100 µg/kg atrazine (ATZ low), 10 me/kg atrazine (ATZ high), or vehicle on

gestational day l through postnatal day …

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 …

Contribution Of Nucleus Accumbens Core To Impulsive Choice: Role Of Dopamine And Glutamate Systems, Justin R. Yates

Theses and Dissertations--Psychology

Impulsive choice refers to the inability to delay gratification and is associated with increased drug abuse vulnerability. Understanding the underlying neural mechanisms linking impulsive choice and drug abuse can contribute to improved treatment options for individuals with substance use disorders. Evidence suggests a major role for nucleus accumbens core (NAcc) in impulsive choice and the reinforcing effects of drugs of abuse. The neurotransmitters glutamate (Glu) and dopamine (DA) are implicated in the neural adaptations observed in drug addiction; however, the role of intra-NAcc Glu and DA in impulsive choice is unclear. Rats were trained in a delay discounting task, in …

Sex Differences In The Dopaminergic Regulation Of Courtship, But Not Pairing Behaviors In Zebra Finches, Erin Marie Lowrey

Wayne State University Theses

Dopamine is one of the key ingredients in the glue that cements social bonds in vertebrates. The D2 dopamine receptor has been implicated in the regulation of monogamous pair bonding in the prairie vole. While dopamine affects courtship behaviors in the male zebra finch, the behavioral role of dopamine acting at D2 receptors in both males and females deserves further attention. We hypothesized that the D2 receptor would regulate courtship and pairing behaviors in the male and female zebra finch. Sixteen males and females were tested using a repeated measures design. On day 1, the zebra finches were injected with …

The Effects Of Extended Access To Methamphetamine Self-Administration On Dopaminergic Markers In The Striatum, Joe Luevano

Open Access Theses & Dissertations

Methamphetamine (METH) abuse is a persistent problem in the U.S. and abroad. Escalation of METH use among independent users occurs for a variety of physiological and psychological reasons. Methamphetamine dependence may be attributed to the rewarding effect of this drug via the dopaminergic systems of the central nervous system (CNS). The presence of METH in the CNS increases synaptic release of dopamine. This increase in dopaminergic neurotransmission is thought to be directly attributed to the rewarding effects of METH. Following METH use, compensatory changes have been found to occur in the dopaminergic system during various periods of abstinence. It is …

Dysfunctional Play And Dopamine Physiology In The Fischer 344 Rat, Stephen M. Siviy, Cynthia A. Crawford, Garnik Akopian, John P. Walsh

Psychology Faculty Publications

Juvenile Fischer 344 rats are known to be less playful than other inbred strains, although the neurobiological substrate(s) responsible for this phenotype is uncertain. In the present study, Fischer 344 rats were compared to the commonly used outbred Sprague-Dawley strain on several behavioral and physiological parameters in order to ascertain whether the lack of play may be related to compromised activity of brain dopamine (DA) systems. As expected, Fischer 344 rats were far less playful than Sprague-Dawley rats, with Fischer 344 rats less likely to initiate playful contacts with a playful partner and less likely to respond playfully to these …

Comparison Of Affective Analgesia And Conditioned Place Preference Following Cholinergic Activation Of, Elena Schifirnet

Wayne State University Dissertations

Activation of the dopaminergic mesolimbic reward circuitry that originates in the ventral tegmental area (VTA) is postulated to preferentially suppress affective reactions to noxious stimuli (affective analgesia, AA). VTA dopamine neurons are activated via cholinergic inputs, and we have observed that microinjections of the acetylcholine agonist carbachol suppressed vocalizations of rats that occur following administration of brief (1 sec) tail-shocks (vocalization afterdischarges = VAD). VADs are a validated rodent model of pain affect. In addition, the capacity of carbachol to support reinforcement appears to be regionally dependent within VTA. Ikemoto and Wise (2002) reported that carbachol was self-administered in the …

Characterization Of The Behavioral And Neurochemical Effects Of Nicotine Withdrawal In Adolescent And Adult Rats., Luis Alberto Natividad

Open Access Theses & Dissertations

Previous studies have demonstrated that the behavioral effects of nicotine withdrawal are lower in adolescent versus adult rats. However, the neurochemical mechanisms that mediate these developmental differences are presently unclear. Much work has shown that nicotine reward is mediated via enhanced dopamine neurotransmission in the mesolimbic pathway which originates in the ventral tegmental area (VTA) and terminates in several forebrain structures including the nucleus accumbens (NAcc). More recently, studies have shown that nicotine withdrawal produces a decrease in NAcc dopamine transmission, an effect that is believed to serve as a neurochemical marker of withdrawal in adult rodents. The goal of …