Neuroscience and Neurobiology Commons^™

Functional Characterization Of The Arginine Vasotocin 4 Receptor (Vt4r) In Sensory Circumventricular Organs Of The Chicken Gallus Gallus, Nguiessan Alphonse Aman

Graduate Theses and Dissertations

Past studies have shown that the avian vasotocin 4 receptor (VT4R), homologous to the mammalian arginine vasopressin receptor 1a (V1aR/AVPR1A) is involved in immobilization stress. It was not known, however, whether the receptor is also associated with osmotic stress, and if so, what brain regions may be involved. Four treatment groups of chicks were used for the study. One group was subjected to 1h immobilization stress and two groups were administered intraperitoneal injection of 3 M NaCl or 0.15 M NaCl. One additional group served as controls. After 1 h, blood samples were taken for the determination of plasma levels …

Gene Regulatory Pathways Driving Central Nervous System Regeneration In Zebrafish, Ishwariya Venkatesh

Theses and Dissertations

Damage to the central nervous system (CNS) circuitry of adult mammals results in permanent disability. In contrast, the ability to regenerate damaged CNS nerves and achieve functional recovery occurs naturally in fish. The ability of fish to successfully regrow damaged CNS nerves is in part a consequence of their ability to re-express key neuronal growth-associated genes/proteins in response to CNS injury. On such protein is Growth-Associated Protein-43 (Gap43), a protein which is highly enriched in axonal growth cones during CNS development and regeneration. Experiments conducted in mammals have demonstrated that ectopic expression of GAP-43 improves axonal re-growth after injury. Using …

A Comprehensive Study Of The Effects Of Neurotoxins On Noradrenergic Phenotypes, Neuronal Responses And Potential Intervention By Antidepressants In Noradrenergic Cells, Yan Wang

Electronic Theses and Dissertations

It has been reported that locus coeruleus (LC) degeneration precedes the degeneration of other neurons in the brain in some neurodegenerative diseases like Alzheimer’s disease (AD) and Parkinson’s disease (PD). However, the precise mechanisms of neurodegeneration remain to be elucidated. N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) has been widely used as a noradrenergic neurotoxin in the development of AD and PD animal models for specific LC degeneration. However, the precise mechanism of action of DSP4 remains unclear. An increased systemic DNA damage caused by neurotoxin or oxidative stress has been found to be related to the pathogenic development of neurodegeneration. The process of neurodegeneration …

The Role Of The Striatal Neuropeptide Neurotensin In The Methamphetamine-Induced Neural Injury In Mice, Qingkun Liu

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) is a widely abused psychostimulant that induces neurotoxicity to several brain regions, including the striatum. Similar to dopamine (DA) in chemical structure, METH can be transported into DA pre-synaptic terminals, evoking the neurodegeneration in DA terminals and post-synaptic striatal neurons. Despite the critical role of DA in METH-induced neurodegeneration, no pharmaceutical therapeutics has been approved for these conditions. It is therefore essential to investigate the endogenous factors regulating the dopaminergic system. The neuropeptide neurotensin has emerged as a potential modulator of METH-induced striatal neurodegeneration mainly due to its intimate interactions with dopamine in the striatum.

In this study, …

Novel Strategies To Modulate Synaptic Communication And Investigate The Role Of Hdac6 In Alzheimer’S Disease, Kathryne A. Medeiros

Doctoral Dissertations

Neuronal communication is mediated by chemical signaling at the synapse. The underlying molecular mechanisms of learning and memory are poorly understood. Very few tools are available to study how memories are formed in the mammalian brain. This dissertation focuses on developing novel strategies to study neural activity. Here we develop and use a chemical-genetic approach to enable target-specific photocontrol of inhibitory synaptic neurotransmission of GABA_A receptor subtypes. The tools developed here selectively photocontrolled GABA_A receptor subtypes. This enabled the investigation of the functional role these receptor subtypes have in inhibitory synaptic neurotransmission. This dissertation also focuses on identifying …

Propagation Of Oligomeric Α-Synuclein And Amyloid-Β: Implications For Parkinson's And Alzheimer's Diseases, Matthew Stephen Planchard

Master's Theses

The aggregation of amyloidogenic proteins is a critical event in the pathology of a variety of neurodegenerative diseases, including Alzheimer’s disease (AD) and Parkinson’s disease (PD). The proteins α-synuclein (αS) and amyloid-β (Aβ) are involved in the formation of amyloid lesions observed in PD and AD, respectively. Both PD and AD exhibit a significant amount of co-pathology in clinical settings, and the αS and Aβ proteins have been shown to interact in vitro. Recent experimental consensus has shown oligomeric species to be significant, if not primary, sources of toxicity in these diseases. …

Leptin Resistance Induced Obesity And Diabetes Promote Neuropathological Changes In The Aging Brain, Thomas Platt

Theses and Dissertations--Molecular and Cellular Biochemistry

The aging brain is prone to the development of pathology and dementia. With a rapidly growing elderly population diagnoses of neurodegenerative diseases, such as Alzheimer’s disease (AD), frontotemporal dementia (FTD), and Parkinson’s disease are on the rise. Additionally, diabetes and obesity are linked to an increased risk of dementia. The convergence of this increasingly aged population with the obesity and diabetes epidemic give rise to new concerns regarding the future of prevention and treatment of neurodegenerative diseases. Our lab has previously shown that leptin, an adipokine involved in signaling satiety to the hypothalamus, can modulate the generation of the amyloid …

Mediation Of Recurrent Hypoglycemia's Physiological And Behavioral Effects In The Hippocampus By Glucocorticoids, Danielle Osborne

Legacy Theses & Dissertations (2009 - 2024)

Recurrent hypoglycemia (RH) occurs with the over administration of insulin resulting in severe hypoglycemia on a repetitive basis. This occurs most commonly among Type I Diabetics who rely on exogenous insulin replacement for management of their disease; however it is becoming increasingly common among Type II Diabetics. Although cognitive deficits are reported during hypoglycemia, the period following restoration of euglycemia has been denoted by improved hippocampally-mediated short-term and working memory in humans and rodents, respectively. RH is also associated with an altered glucocorticoid secretion profile in response to hypoglycemia. In vitro and in vivo approaches were utilized with the goal …

Mechanisms To Mitigate Neurodegeneration By Maintaining Mitochondrial Health, Parijat Kabiraj

Open Access Theses & Dissertations

Cerebral accumulation of amyloidogenic protein aggregates is most frequently observed in the pathogenesis of neurodegenerative diseases. Recent studies showed prion like spreading of beta amyloid (A beta) in Alzheimer's disease (AD) and alpha synuclein protein in Parkinson's disease (PD) brain. Failure or compromise to the chaperone activity of protein disulfide isomerase (PDI) is also been reported as a major factor of aggregate formation. Nitrosative stress mediated S-nitrosylation (SNO) of protein disulfide isomerase (PDI), a housekeeping oxidoreductase, has been implicated in the pathogenesis of sporadic PD and AD. Mitochondrial dysfunction, leading to elevated levels of reactive oxygen species (ROS), is associated …

Characterization Of The Transporter Protein Sodium-Potassium Adenosine Triphosphatase In The Myelin Membrane, Dara E C Schaefer

Theses and Dissertations (Comprehensive)

Sodium-potassium adenosine triphosphatase (Na⁺/K⁺-ATPase) is an integral membrane protein with known involvement in the maintenance of resting membrane potentials, nutrient uptake, cellular signal transduction, and cell-cell adhesion. The functional enzyme contains a catalytic alpha subunit and a glycosylated beta subunit, of which three isoforms of each are known to exist in the central nervous system (CNS). Altered expression and/or activity of Na⁺/K⁺-ATPase subunit isoforms has been previously implicated in the pathophysiology of several neurological disorders. This study characterized Na⁺/K⁺-ATPase expression and distribution in the myelin membrane, identified its …