Medicine and Health Sciences Commons^™

Methamphetamine-Induced Dna Double-Stranded Breaks: The Impact Of The Dopamine Transporter And Insights Into The Mechanisms Of Dna Damage In Mouse Neuro 2a Cells, Lizette Couto

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) abuse remains a global health concern, with emerging evidence highlighting its genotoxic potential. In the central nervous system METH enters dopaminergic cells primarily through the dopamine transporter (DAT), which controls the dynamics of dopamine (DA) neurotransmission by driving the reuptake of extracellular DA into the presynaptic neuronal cell. Additional effects of METH on the storage of DA in synaptic vesicles lead to the dysregulated cytosolic accumulation of DA. Previous studies have shown that after METH disrupts intracellular vesicular stores of DA, the excess DA in the cytosol is rapidly oxidized. This generates an abundance of reactive oxygen species …

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 …

A Comparison Of Pm-Nato3’S Influence On Neural Progenitors And Mature Dopamine Neurons, Mary E. West

Masters Theses

This thesis presents significant findings regarding the role of PM-Nato3 in its interaction with developing neurons in the context of Parkinson's disease (PD) and regenerative medicine. We investigated the effects of PM-Nato3 on dopamine (DA) neurogenesis under different culture conditions, both in vitro and in vivo. In the standard dopaminergic culture condition, PM-Nato3 potentially increased the speed of DA neuron production but did not significantly increase the yield of DA neurons. In a minimal culture condition, there was no notable difference between the control and PM-Nato3 conditions, suggesting minimal impact on DA neurogenesis. In vivo studies using a mouse model …

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 …

Design And Synthesis Of Substituted N,3,3-Triphenylpropanamide And 1-Benzhydryl-N-Phenylazetidine-3-Carboxamide Analogs And Their Biological Evaluation, Michael Dorogan

Theses and Dissertations

As D₁R agonism has significant implications in the treatment of cognitive deficits, we sought to develop novel D₁R PAMs, through the derigidification of BMS D₁R PAM hit compound. While we were able to synthesize derigidified analogs of the BMS hit compound, derigidification did not produce active D₁R ligands.

A Polypharmacological Approach To Relapse Prevention In An Animal Model Of Heroin Addiction, Scott T. Ewing

Dissertations, Theses, and Capstone Projects

Chemical compounds that target dopamine (DA) D1 or D3 receptors have shown promise as potential interventions in animal models of cue-induced relapse. However, undesirable side effects or pharmacodynamic profiles have limited the advancement of new compounds in preclinical studies when administered as independent treatments. In this series of experiments, we explored the effects of co-administration of a D1-recepter partial agonist (SKF 77434) and a D3-receptor antagonist (NGB 2904) in heroin-seeking rats within a ‘conflict’ model of abstinence and cue-induced relapse. Rats were first trained to press a lever to self-administer heroin and drug delivery was paired contingently with cues (e.g., …

Parkinson's Disease And Anesthesia, Anthony Brusadin

Nursing Student Class Projects (Formerly MSN)

Parkinson’s disease is one of the most common neurodegenerative disorders in the world and is rapidly growing. With the global population living longer there will be more people that develop Parkinson’s like the average person’s life expectancy increases. With no cure and only treatment and management of the symptoms, it is important for research to continue to find better treatment options and potentially a cure. In the world of anesthesia patients with Parkinson’s are more difficult to manage with sedation medication because of the lower dopamine levels the patient has. It is important to stay updated on how to prepare …

Synthesis And Evaluation Of C-10 Nitrogenated Aporphine Alkaloids At Serotonin And Dopamine Receptors, Anupam Karki

Dissertations, Theses, and Capstone Projects

Aporphine alkaloids, belonging to the isoquinoline class of compounds, have been investigated as a potential source of ligands for Central Nervous System (CNS) receptors. Previous research indicates that the aporphine scaffold may be manipulated to synthesize selective ligands for serotonin and dopamine receptors. Novel aporphine alkaloids containing C10 nitrogen substitutions were synthesized, and their affinities were evaluated at serotonin (5-HT1A, 5-HT1B, 5-HT2A, 5-HT7A) receptors and dopamine (D1, D2, D3, D4, and D5) receptors. Two series of racemic aporphine compounds with C10 nitrogenous functionalities were synthesized and analyzed at the aforementioned receptors. The first series of aporphine alkaloids contain C10 nitro, …

Exploring The Dopamine Transporter Utilizing A Two-Pronged Approach With Novel Cathinone Analogs And Mutant Dopamine Transporters, Charles B. Jones Iii

Theses and Dissertations

The dopamine transporter (DAT) is responsible for the removal of the neurotransmitter from the synaptic gap and a therapeutic target for a multitude of drugs. While the ortholog Drosophila melanogaster dopamine transporter (dDAT) and human serotonin transporter (hSERT) have resolved structures, the human dopamine transporter (hDAT) does not. A 3-D computational homology model of hDAT was constructed for the study of molecular interactions with agents within the central binding site (S1) of the transporter.

Synthetic cathiones are a class of abused stimulant drugs that primarily target DAT. Greater than 150 cathinones have been identified on the clandestine market but there …

The Impact Of Levodopa Administration On Learning From Short-Term And Long-Term Action Consequences: A Paradigm Validation., Masood Rezaei

Electronic Thesis and Dissertation Repository

Behavioral and neuroimaging studies have identified two valuation systems in the human brain for controlling behavior known as model-free (MF) and model-based (MB). MF is based on immediate evaluation and MB is based on long-term evaluation of the outcome of our decisions. Previous studies suggest that dopamine baseline activity may play an important role in the balance between the two systems and determine how they compete or interact in controlling our actions. The overarching aims of this study is to investigate the impact of levodopa administration on learning from immediate and long-term action consequences, and to dissociate the role of …

The Determination Of Phosphorylation Of Nato3 By Pka, Miranda M. Regenold

Masters Theses

One of the leading regulators of neuronal cell differentiation in the CNS is the family of basic helix–loop–helix (bHLH) transcription factors. One of these proteins, Nato3, is associated with the formation of dopaminergic neurons. Transcription factors can be regulated by kinase activity, and in order to detect the associated change of phosphorylation of Nato3, we have generated Nato3 with specific epitope tags that allow for the detection and isolation of the Nato3 protein. Through subcloning techniques and a successful transformation of the Nato3 gene with the sequences of the 3X-Flag epitope and the Myc epitope into the pcDNA3.0 vector, we …

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 …

Behavioral And Neurobiological Evidence Of Epigenetic Transmission In The Neonatal Quinpirole Rodent Model Of Schizophrenia, Wesley Gill

Electronic Theses and Dissertations

Quinpirole is a dopamine D2 receptor agonist that if administered to rats from postnatal day (P)1-21 results in increased dopamine D2 receptor sensitivity throughout the animal’s lifetime. This increase in receptor sensitivity is consistent with schizophrenia. This model has additional consistencies with human schizophrenia, including sensorimotor gating deficits, enhanced behavioral and neurobiological responses to nicotine, and protein alterations consistent with the disorder. In this study, a second generation of the neonatal quinpirole (NQ) rodent model was created to investigate if long term changes caused by NQ treatment would be passed to offspring. NQ treated rats were mated and their offspring …

Activation Of The Sonic Hedgehog Effector Smoothened Counteracts L-Dopa Induced Dyskinesia By Restoring Cholinergic Interneuron Function, Lauren Malave

Dissertations, Theses, and Capstone Projects

Many types of neurons act as multimodal signaling centers. Yet, we have only limited insight into the regulation and functional consequences of neuronal co-transmission. For example, dopamine (DA) neurons, whose degeneration causes motor deficits characteristic of Parkinson’s Diseases (PD), communicate with all their targets by DA but only a selective subset of their targets using GABA, Glutamate, and the secreted cell signaling protein Sonic Hedgehog (Shh). It is unknown whether Levo-dopamine (L-Dopa) induced dyskinesia (LIDs), a severely debilitating side effect of DA supplementation in PD, might appear because DA neuron targets are exposed to high DA- but low Shh- signaling …

Dopamine-Dependent Transcriptional Dynamics In Striatal Physiology And Cocaine Reward, Morgan Elizabeth Zipperly

All ETDs from UAB

Exposure to drugs of abuse alters transcriptional programs and neuronal activity, leading to long-lasting cellular and behavioral adaptations that may contribute to addiction. The nucleus accumbens (NAc), part of the mesocorticolimbic dopamine pathway, plays a central role in motivation, reward, and reward-related learning, and this brain region is highly implicated in the development and maintenance of addiction. However, the specific contributions of defined cell populations in the NAc to drug reward processes is still poorly understood. Here, we used electrophysiological, optogenetic, and single-nucleus RNA-sequencing (snRNA-seq) approaches in a rodent model system to define the acute physiological and transcriptional responses of …

Mechanisms Of Dopamine-Induced Methamphetamine Neurotoxicity, Melinda L. Asbury

Theses, Dissertations and Capstones

Methamphetamine (MA) neurotoxicity is particularly evident in the striatum where it causes extensive dopamine (DA) release and results in neurodegeneration. To identify specific signaling pathways and macromolecules involved in postsynaptic DA-induced striatal toxicity we used a SK-N-MC cell model that mimics postsynaptic D1 receptor-expressing striatal neurons. The cells were treated for 6-24 h with 0-50 µM DA. The concentration was chosen to impart physiological relevance to the study as it mirrors [DA] found within the striatum following MA exposure. We show that 25-50 µM DA resulted in protein changes consistent with nitro(oxidative) stress as well as enhanced cleavage of caspase …

Astrocyte Sensitivity To Dopamine In Culture And Ex Vivo, Ashley L. Galloway

Theses and Dissertations

Dopamine is critical for processing of reward and etiology of drug addiction. Astrocytes throughout the brain express dopamine receptors, but consequences of astrocytic dopamine receptor signaling are not well established. This thesis illustrates effects of dopamine on cultured astrocytes and astrocytes in brain slices (ex vivo). In striatal cultures, extracellular dopamine triggered changes in astrocytic Ca²⁺ signaling and rapid concentration-dependent stellation of astrocytic processes that was not a result of dopamine oxidation, but instead relied on both cAMP-dependent and cAMP-independent dopamine receptor signaling. To isolate possible mechanisms underlying these structural and functional changes, whole-genome RNA sequencing was …

The Acute Effects Of Melatonin On Striatal Dopamine Release: Progressive Electrochemical Analysis In An Ex Vivo Mouse Model Utilizing Fast Scan Cyclic Voltammetry, Kevin D. Hughes

Masters Theses

The caudate putamen is a sub region of the basal ganglia, containing neural tracts important for cognition, reward learning, and voluntary motor function. Dopamine (DA) signaling received from the dopaminergic neurons of the substantia nigra pars compacta mediate locomotion, degradation of which is the characteristic neuropathology for Parkinson’s disease (PD). PD is an initially neurovegetative motor disorder but can progress to include cognitive impairments as well. Sundowner’s syndrome (SS) has been observed in patient populations with neurodegenerative diseases, characterized by the decline of cognition into evening hours. Due to the circadian influence which the hormone melatonin has on the sleep-wake …

Green Tea Extract, Epigallocatechin Gallate, Protect Against Methamphetamine-Induced Striatal Neurotoxicity In Mice, Allen L. Pan

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) is a strong psychostimulant and its exposure can lead to serious neurological complications. METH-induced neuronal injury is the result of a complex interplay of different factors including dopamine (DA) overflow, oxidative stress and neuroinflammation. Although the mechanisms of METH-induced neurotoxicity have been extensively studied, there is still no effective therapeutic treatment. Therefore, it is essential to study potential drug candidates that can treat METH-induced neurotoxicity. Green tea extract, epigallocatechin gallate (EGCG), has emerged as a neuroprotective agent that can protect against several neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. Recently, our lab has shown that EGCG prevents …

Transcriptional Dynamics Of Dopaminergic Signaling, Katherine Elizabeth Savell

All ETDs from UAB

Drugs of abuse increase dopamine concentrations in the nucleus accumbens, a key reward structure that integrates contextual and cue-related information and regulates motivated behavior. This surge of dopamine triggers cell signaling cascades that converge in the nucleus to cause changes in gene expression, which are thought to lead to the observed functional and structural alterations in the reward circuit after exposure to drugs of abuse. However, while various drugs of abuse cause transcriptional changes, previously available tools have not had the capacity to deeply characterize these gene programs. Therefore, we optimized a dual lentivirus CRISPR system for targeted gene modulation …

Structure-Activity Relationship Studies Of Synthetic Cathinones And Related Agents, Rachel A. Davies

Theses and Dissertations

Synthetic cathinones and related agents represent an international drug abuse problem, and at the same time an important class of clinically useful compounds. Structure-activity relationship studies are needed to elucidate molecular features underlying the pharmacology of these agents. Illicit methcathinone (i.e., MCAT), the prototype of the synthetic cathinone class, exists as a racemic mixture. Though the differences in potency and target selectivity between the positional and optical isomers of synthetic cathinones and related agents have been demonstrated to have important implications for abuse and therapeutic potential, the two MCAT isomers have never been directly compared at their molecular targets: the …

When Brain Stimulation Backfires, Sarah Beth Bell

Theses and Dissertations--Psychology

tDCS brain stimulation does not always work in the intended direction. It has been found to sometimes worsen behavior rather than improve it. A preliminary study shows that people high on sensation-seeking and lack of premeditation were prone to reverse effects of tDCS on performance on a Stop Signal Task. Both of these constructs are related to dopamine levels. Study 2 seeks to intentionally cause a reverse effect of tDCS by increasing participants’ dopamine levels via caffeine. There was not a significant interaction between tDCS and caffeine on errors on the Stop Signal Task in this study. However, other factors …

Neuropsychological Correlates Of Striatal Dopaminergic Dysfunction In Parkinson’S Disease, Brittany D. Walls

Theses and Dissertations--Psychology

Parkinson’s disease (PD) is a common neurodegenerative disorder associated with dysfunction of the basal ganglia, which contributes to a range of motor, cognitive, and affective symptoms. Striatal dopaminergic deficits are one of the core pathological mechanisms thought to contribute to the extra-motor (i.e., cognitive and affective) symptoms in early PD. The present study investigated the relationship between striatal dopaminergic integrity and cognition in 21 patients with PD and 21 age and education matched controls. Each individual underwent dopamine transporter (DaT) imaging with single photon emission computed tomography (SPECT) (i.e., DaTscan) and standardized neuropsychological testing. Strong positive associations were found between …

Effects Of Natural Antioxidants On Motor And Cognitive Deficits In An Animal Model Of Aging And Obesity And Dopaminergic-Like Sh-Sy5y Cell Line, Sneha Potdar

Electronic Theses and Dissertations

Aging is a universal phenomenon. One of the greatest challenges faced by the elderly population is to sustain a healthy standard of living. Advancing age is associated with increased motor and cognitive deficits. Loss of balance, falls, hip fractures, and poor memory all contribute to a decline in the quality of life of the aging population. While ongoing research is making advances to find therapeutic interventions for neurodegenerative disorders like Parkinson’s and Alzheimer’s diseases, there is a pressing need to address deficits associated with normal aging.

Increase in oxidative stress and a decline of antioxidant mechanisms with aging have been …

An Interface Of The Taste And Reward Systems In The Brainstem And Its Role In Feeding, Louis Saites

Theses and Dissertations (ETD)

We eat what tastes good. We also eat because it is necessary for our health. In fact, some of the most nutritious foods (e.g., vegetables) are often less appetizing, and the tastiest (e.g., fast food, ice cream) may be the least healthy. Despite the former, we may also have a lower limit of what we accept at which point nutrition becomes irrelevant (e.g., “spinach is just too yucky”). Further, we may eat unhealthily because of overwhelming urges. We investigated the complex interactions of taste and feeding at the neurobiological level using the experiments described.

In one sense, this neurobiology begins …

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 Combined Neuropharmacology And Toxicology Of Major 'Bath Salts' Constituents Mdpv, Mephedrone, And Methylone, Serena Allen

Electronic Theses and Dissertations

The synthetic cathinones, 3,4- methylenedioxypyrovalerone (MDPV), 4-methylmethcathinone (mephedrone), and 3,4- methylenedioxymethcathinone (methylone), gained worldwide notoriety as the psychoactive components of ‘bath salts;’ a marketing term used to circumvent federal drug laws and permit their legal sale. Previous studies have shown that these drugs share pharmacological characteristics with cocaine and the amphetamines, however, descriptions of their neurotoxic properties are limited. Moreover, while forensic analysis has revealed that the most frequently abused bath salts ‘brands’ contain binary and ternary mixtures of MDPV, mephedrone, and methylone, the majority of preclinical research has focused on explicating the individual effects of these drugs. Therefore, the …

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 …

Dopamine Levels In The Brain Of Rat Models Of Human Rheumatoid Arthritis, Amelia Stinson

Theses & Dissertations

Research Focus. Rheumatoid arthritis (RA) is a chronic, debilitating, autoimmune disease that causes the destruction of bone tissue and the articular structures of joints. At least 30% of RA patient populations have cognitive impairment. Acidic dopamine (DA) is the principal neuroimmunotransmitter that links the central nervous system and peripheral nervous system together. The aim of the present study was to determine the levels of DA and its two acidic metabolites: 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in arthritic induced rats, and whether their levels vary across four different parts of the brain: amygdala (AMG), front cerebral cortex (CX), hippocampus …

Pitx3null Mutant (Striatal Dopamine-Deficient) Mice Have Exaggerated Spiny Projection Neuron Responses To L-Dopa And D1 Agonism And Lack Baseline Striatonigral Spiking, Ben Sagot

Theses and Dissertations (ETD)

L-3,4 dihidroxyphenylalanine (l-DOPA) strongly stimulates motor activity in parkinsonian patients and animal models of Parkinson's disease. Severe striatal dopamine (DA) loss characterizes Parkinson's disease and its animal models. Given the canonical rate model of Parkinson's Disease pathophysiology based on differences in DA pharmacology manifesting as electrophysiological differences in striatal projection neuron (SPN) spike rates, SPNs should increase spiking during the motor response to l-DOPA. In fact, stimulating specific subsets of these neurons to spike in freely-moving wild type and parkinsonian animals causes or inhibits motor activity as predicted. However, pharmacological effects of DA deficiency, let alone those of DA replacement, …