Behavioral Neurobiology Commons^™

Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng

Electronic Thesis and Dissertation Repository

Nicotine dependence is causally linked to increased risk of mood/anxiety disorders in later life. Females are reported to experience a higher prevalence of anxiety/depressive disorders and challenges in smoking cessation therapies, suggesting a potential sex-specific response to nicotine exposure and mood/anxiety disorder risk. However, pre-clinical evidence of sex-specific responses to adolescent nicotine exposure is unclear. Thus, to determine any sex differences in anxiety/depressive-related outcomes, adolescent male and female Sprague Dawley rats received nicotine (0.4 mg/kg; 3x daily) or saline injections for 10 consecutive days, followed by behavioural testing, in-vivo electrophysiology and Western Blot analyses. Our results revealed that adolescent nicotine …

Role Of Nucleus Accumbens Dopamine Receptor Signaling In The Suppression Of Punished Reward Seeking, Grace M. Joyner, Anna Caroline Toburen

Senior Theses

Previous studies have shown that within the nucleus accumbens (NAc), a brain region associated with motivation and reinforcement learning, activity of neurons expressing the dopamine D2 receptor (D2R neurons) act as a “break” on risky behavior associated with negative outcomes. Moreover, when these neurons are stimulated, rats were found to become more risk averse. However, the impact of dopamine signaling through NAc D2R neurons in risk avoidance is still unclear. To further explore the role of NAc dopamine signaling in punished reward-seeking, we tested rats in a novel punished food-seeking paradigm in which subjects are trained to choose between a …

Dendritic Spine Density And Morphology In The Dorsolateral Striatum Following A High Fat Diet, Tikva Nabatian

Dissertations, Theses, and Capstone Projects

Obesity rates have been dramatically rising in recent years and in 2017-2018 more than 42% of adults in the United States were obese. Obesity is associated with numerous health problems, including cardiovascular disease, stroke, insulin resistance, and type II diabetes. The prevalence of highly palatable and calorically dense foods high in fats and sugars is a significant factor in the increase in obesity rates. Many suggest that palatable food affects the brain in ways similar to drugs of abuse, reinforcing the consumption of highly palatable foods in the same way drugs reinforce drug use. While numerous weight loss programs and …

Cue Reactivity In Electronic Cigarette Users With Sign-Tracking Or Goal-Tracking Behaviors, Polina Krom

Graduate Theses, Dissertations, and Problem Reports

Polina Krom

Cue reactivity is an important predictor of addiction course and relapse. However, cue reactivity is only observed after an addiction develops. As such, it is unclear to what degree cue reactivity represents a state stemming from the addiction process versus a trait-like propensity towards developing cue-reward associations. Work in animal models has pointed to important individual differences in trait-like inclination to attribute incentive salience to reward-predictive cues that is associated with addiction-relevant behavioral and neurobiological features. These individual differences manifest as sign-tracking (ST) and goal-tracking (GT) behaviors during Pavlovian conditioning. Little research has attempted to translate ST and …

Dietary Regulation Of Silent Synapses In The Dorsolateral Striatum, Allison M. Meyers

Dissertations, Theses, and Capstone Projects

Obesity and drugs of abuse share overlapping neural circuits and behaviors. Cravings for drugs of abuse increase during abstinence, a phenomenon known as incubation. In obesity, increased craving is observed in individuals during dieting. Diets often fail, with return to- or increase above- original weight. The extent to which this reflects an incubation phenomenon has not been carefully examined. One mechanism underlying incubation is the reemergence of a developmental mechanism called silent synapses. Silent synapses are 'temporary' synapses that are important for remodeling brain circuits. They are prevalent during early development but largely disappear by adulthood. Drugs of abuse increase …

Sex Differences In Lateral Hypothalamic Extracellular Glucose Concentrations During Cumulative Dosing Of Methamphetamine In Rats, Joshua A. Jolton

Honors Theses

The present study experimentally investigated sex differences in lateral hypothalamic glucose concentrations following cumulative dosing of methamphetamine. Male (n=17) and female (n=11) rats were surgically implanted with enzyme-based glucose biosensors in the lateral hypothalamus. Rats then received a saline injection followed by four methamphetamine doses (0.025 mg/kg, 0.05 mg/kg, 0.1 mg/kg, and 0.2 mg/kg) spaced 55 minutes apart. We found that while there was a general decrease in glucose baseline throughout the study for both sexes, the magnitude of the decrease was significantly greater in females compared to males. On a rapid timescale, fixed sex effects existed at the lower …

Hiv-1 Tat Interactions With Opioids Are Modulated By Progesterone And Estradiol, Dejun Jackson

Honors Theses

HIV infection and combined substance abuse are comorbid epidemics. Previous studies show that concurrent opioid drug use may potentiate HIV-1-mediated neurotoxicity partly via interactions with opioids. Preclinical studies suggest that the HIV-1 trans-activator of transcription (Tat), an HIV regulatory protein, can synergize with opioids to exacerbate its already neurotoxic effects. However, its interactions with clinical opioids, such as oxycodone, have yet to be elucidated. Additionally, Tat disrupts a number of systems including the dopaminergic system, which contribute to its capacity to potentiate the rewarding effects of abused drugs. Although the neurotoxic effects of Tat may be inhibited by gonadal steroids …

Effects Of Repeated Intermittent Episodes Of Social Stress On The Acquisition And Extinction Of A Reward-Seeking Task, Nikki Sullivan

Honors Theses

Repeated exposure to stress is known to have a myriad of effects on the brain, contributing to the development of psychiatric disorders, such as anxiety, depression, and drug addiction. For example, rats undergoing repeated social stress develop increased cocaine self-administration. These effects of stress are not well-understood and are related to changes in the brain reward system. This study investigated the effects of repeated social stress on reward-seeking behavior via the acquisition and extinction of a discriminative stimulus (DS) task and on anxiety-like behavior in the elevated plus maze (EPM). Male rats underwent intermittent social defeat (4 sessions in 10 …

Addictions, Behavioral Addictions, And Pathological Internet Use As Internet Addiction - A Literature Review, Vy K. Nguyen

Publications and Research

Excessive and pathological uses of the Internet are observed and discussed often in our modern conversations. Access to the Internet has become so convenient that these behaviors can lead to consequences in many areas of our lives from social relationships to academic and professional work performance. A common term that people use to address this pattern of behaviors is “Internet Addiction” or more specific ones, such as “Social Media Addiction” or “Online Gaming Addiction.” However, in clinical psychology, addiction has its own specific definitions. It refers to a category and set of criteria that are distinguished from other mental disorders …

The Winding Road To Relapse: Forging A New Understanding Of Cue-Induced Reinstatement Models And Their Associated Neural Mechanisms, Mark D. Namba, Seven E. Tomek, M. Foster Olive, Joshua S. Beckmann, Cassandra D. Gipson

Psychology Faculty Publications

In drug addiction, cues previously associated with drug use can produce craving and frequently trigger the resumption of drug taking in individuals vulnerable to relapse. Environmental stimuli associated with drugs or natural reinforcers can become reliably conditioned to increase behavior that was previously reinforced. In preclinical models of addiction, these cues enhance both drug self-administration and reinstatement of drug seeking. In this review, we will dissociate the roles of conditioned stimuli as reinforcers from their modulatory or discriminative functions in producing drug-seeking behavior. As well, we will examine possible differences in neurobiological encoding underlying these functional differences. Specifically, we will …

Prefrontal Cortex Dopamine Transmission Regulates Emotional Memory Processing And Morphine Reward Salience: Implications For Post-Traumatic Stress Disorder And Addiction Comorbidity, Jing Jing Li

Electronic Thesis and Dissertation Repository

Post-Traumatic Stress Disorder (PTSD) and addiction are strongly comorbid. However, the underlying neural mechanisms by which traumatic memory recall may increase addiction liability are poorly understood. The inability to suppress memory recall related to either stressful or rewarding, drug-related experiences may be an underlying neuropsychological feature capable of triggering both PTSD or addiction-related behaviours. Our previous research has shown that transmission through dopamine (DA) D₄ and D₁ receptor subtypes (D₄R, D₁R) within the prefrontal cortex (PFC) strongly modulates emotional memory acquisition and recall (Lauzon et al., 2009). Using olfactory fear conditioning and morphine conditioned …

The Effects Of Chronic Partial Sleep Deprivation And Chronic Voluntary Alcohol Consumption On Δfos B Accumulation, Kristian Ponder

Masters Theses, 2010-2019

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors. Accumulation of the transcription factors ΔFosB is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between ΔFosB and chronic alcohol consumption. There were four experimental groups in this study: Control (C), Sleep Deprivation only (SD), Alcohol Exposure only (AO), and both sleep deprivation and alcohol exposure (B). Levels of ΔFosB accumulation in the Nucleus Accumbens (NAc) revealed a significant main effect of sleep deprivation, but no …

Behavioral And Neural Mechanisms Of Impulsive Choice, Jesse Mcclure

Doctoral Dissertations

Impulsive choice is defined as the preference for a small immediate reward over a larger delayed reward. Individual variablity in impulsive choice correlates with many socially relevant behaviors. Although forms of impulsive choice have been studied in both behavioral ecology and psychology, the exchange of knowledge between these fields is just beginning. Drawing from both of these fields will improve our research methods allowing for a more detailed understanding of this complex behavior. Existing tasks to measure impulsive choice conflate the delay and quantity of the reward. To address this, I have drawn from foraging research to establish a method …

Exposure To Kynurenic Acid During Adolescence Increases Sign-Tracking And Impairs Long-Term Potentiation In Adulthood, Nicole E. Deangeli, Travis P. Todd, Stephen E. Chang, Hermes H. Yeh, Pamela W. Yeh, David J. Bucci

Dartmouth Scholarship

Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently, there are few treatments for persons with a dual diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA), a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and …

Sex-Specific Brain Deficits In Auditory Processing In An Animal Model Of Cocaine-Related Schizophrenic Disorders, Patricia A. Broderick, Taylor Rosenbaum

Publications and Research

Cocaine is a psychostimulant in the pharmacological class of drugs called Local Anesthetics. Interestingly, cocaine is the only drug in this class that has a chemical formula comprised of a tropane ring and is, moreover, addictive. The correlation between tropane and addiction is well-studied. Another well-studied correlation is that between psychosis induced by cocaine and that psychosis endogenously present in the schizophrenic patient. Indeed, both of these psychoses exhibit much the same behavioral as well as neurochemical properties across species. Therefore, in order to study the link between schizophrenia and cocaine addiction, we used a behavioral paradigm called Acoustic Startle. …

Identification Of A Molecular Opiate-Addiction Memory Switch In The Basolateral Amygdala, Danika C.A. Lyons

Electronic Thesis and Dissertation Repository

The molecular mechanisms involved in acquiring opiate-related associative memories are largely unknown. One neural region implicated in the formation of opiate-related memories is the basolateral nucleus of the amygdala (BLA). Transmission through dopamine (DA) receptors within the BLA controls the formation of opiate-related reward memories (Lintas et al., 2011; Lintas et al., 2012). Specifically, transmission through DA D1 receptors controls opiate reward memory formation in animals that are previously naïve to opiate exposure. However, once opiate dependence and withdrawal are present, intra-BLA DA-mediated control of opiate reward memory processing switches to a DA D2 receptor substrate. These findings demonstrate a …

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 …