Systems Neuroscience Commons^™

The Effects Of Chronic Nicotine Exposure On Dopamine-Mediated Reinforcement Learning And Striatal Neurotransmission, Srishti Bose

Dissertations, Theses, and Capstone Projects

Tobacco is one of the most widely used substances across the United States; tobacco consumption is linked with several diseases and is one of the leading causes of preventable death in the country. Nicotine is the active substrate found in tobacco products, acting as a stimulant, which reinforces continued use. The introduction of tobacco-free options such as e-cigarettes and oral pouches has driven an increase in nicotine exposure across the population, especially in young adults. Acute nicotine use induces neuroadaptations in the mesolimbic dopaminergic system, which mediates reinforcement learning and addiction, that potentiates reward-related neurotransmission. Furthermore, there are clinical studies …

Perinatal Inflammation And Oxidative Stress Alter Adult Rat (Rattus Norvegicus) Motor Behavior, Alexander Young

Honors College Theses

Recent evidence in comparative animal models suggests that early life exposure to elevated inflammation (via LPS exposure) and oxidative stress (via acetaminophen exposure) may synergistically interact to alter typical neurodevelopmental trajectories, resulting in lasting effects on both behavior and gut-brain neurochemistry. The current study observed emotional and motor behaviors and collected fecal-boli to measure Tyrosine (TE) levels in male and female Long-Evans (Rattus norvegicus) rats. Subjects were either treated with [1] saline [2] lipopolysaccharide (LPS) to introduce an inflammatory state, [3] acetaminophen (APAP) to introduce oxidative stress, or [4] a dual-hit of both LPS + APAP on postnatal day (PD) …

Sequence Learning In A 6-Ohda Mouse Model Of Parkinson’S Disease, Ani Gribbin

Neuroscience Honors Projects

Parkinson’s disease (PD), a neurodegenerative disorder originating in the dopaminergic cells of the basal ganglia, is characterized by severe motor impairments such as tremors, bradykinesia, and postural instability. However, non-motor symptoms impacting sensory systems and cognition are consistently pointed to as more greatly affecting quality of life for PD patients. Cognitive impairments in PD can include changes in reward processing, depression, apathy, and increases in risk-taking behavior. Additionally, learning and memory deficits are seen in PD, specifically in motor sequence learning. Often, the neural correlates of sequence learning impairments are traced to the substantia nigra. However, there is some evidence …

Identification And Delineation Of Neuronal Pathways Underlying Hypophagia, Jing Cai

Dissertations and Theses (Open Access)

In terms of metabolism, eating disorders manifest in two extreme directions: overnutrition, which can lead to obesity, and malnutrition, which can result in underweight or even starvation. Both extremes compromise the quality of life. According to the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) standard, eating disorders affect up to 17.9% of young women and 2.4% of young men. Although eating disorders are primarily defined as mental disorders rather than metabolic disorders, they are intertwined with complex emotions and sensory perceptions. However, in contemporary animal research related to eating disorders and feeding behaviors, the majority of neuroscientists still examine …

Quantifying Psychostimulant-Induced Sensitization Effects On Dopamine And Acetylcholine Release Across Different Timescales, Georg Lange

Dissertations, Theses, and Capstone Projects

Drug-induced behavioral sensitization describes the phenomenon that behavioral response to a drug of abuse is getting stronger if the same psychostimulant is delivered multiple times which is much more pronounced if done in the same environmental context. A proposed neural basis is the formation of an association between contextual cues and the rewarding drug which is mediated by dopamine. Dopamine operates at different timescales and to fully understand dopamine sensitization, it is necessary to investigate dopamine release at slow (tens of minutes) but also faster (sub-second) timescales. But creating a holistic view has been difficult due to a lack of …

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 …

Modeling And Mapping Addiction In The Zebrafish, Danio Rerio, Bradley Serpa

Master of Science in Integrative Biology Theses

Driven by the communication of dopamine, the vertebrate reward system has been evolutionarily conserved to maintain survival and optimize fitness. The neural circuits governing this system integrate sensory stimuli to produce appropriate, self-preserving responses that underlie experience-based learning. In the most primitive vertebrates, dopamine release in neuronal circuits drives homeostatic behaviors, such as seeking nutrients, finding a mate, or avoiding danger. From agnathans to mammals, dopaminergic synthesis and signaling genes and molecules, along with neuronal pathways and reward system-based behaviors, remain highly conserved. Dopamine signaling proteins include two classes of metabotropic G-Protein Receptor Coupled Dopamine Receptors, D1-like (DRD1) and D2-like …

The Integration Of Extrinsic And Intrinsic Neuromodulators In The Olfactory System, Kristyn M. Lizbinski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics by adjusting the biophysical and synaptic properties of neurons. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e. neurons that participate in network coding) or an extrinsic origin (i.e. neurons from independent networks). Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. Furthermore, nervous systems are continually subject to a dynamic cocktail of both intrinsic and extrinsic modulators. However, …

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

LSU 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 …

Distribution And Activation Of Catecholaminergic Neurons In The Brain Of Male Plainfin Midshipman Fish: Divergence In Behavior And Reproductive Phenotype, Zachary Ghahramani

Dissertations, Theses, and Capstone Projects

The plainfin midshipman fish, Porichthys notatus, provides an excellent opportunity for delimiting the influence of neurochemical content on vertebrate vocal behavior, in part because the production and recognition of social-acoustic signals is vital to their reproductive behavior. There are two distinct reproductive male morphs that follow divergent developmental trajectories with corresponding alternative reproductive tactics: type I males are the territorial/nesting morph that vocally court females during the summer breeding season while type II males do not court females, but instead sneak spawn in competition with type I males. Catecholaminergic neurons, which synthesize and release the neurotransmitters dopamine or noradrenaline, …

Dopaminergic And Activity-Dependent Modulation Of Mechanosensory Responses In Drosophila Melanogaster Larvae, Josh S. Titlow

Theses and Dissertations--Biology

A central theme of this dissertation is nervous system plasticity. Activity-dependent plasticity and dopaminergic modulation are two processes by which neural circuits adapt their function to developmental and environmental changes. These processes are involved in basic cognitive functions and can contribute to neurological disorder. An important goal in modern neurobiology is understanding how genotypic variation influences plasticity, and leveraging the quantitative genetics resources in model organisms is a valuable component of this endeavor. To this end I investigated activity-dependent plasticity and dopaminergic modulation in Drosophila melanogaster larvae using neurobiological and genetic approaches.

Larval mechanosensory behavior is described in Chapter 2. …