Neuroscience and Neurobiology Commons^™

The Role Of Oxidative Stress In The Mechanisms Of Ammonia-Induced Brain Swelling And Tolerance In The Goldfish (Carassius Auratus), David F. Jones Lisser Mr.

Theses and Dissertations (Comprehensive)

Toxic build-ups of ammonia can cause potentially fatal brain swelling in mammals, but such swelling is reversible in the anoxia- and ammonia-tolerant goldfish (Carassius auratus). The mechanisms of ammonia-induced brain swelling and tolerance remain elusive, but several studies have suggested a role for reactive oxygen species (ROS), which may damage proteins and lipids in the plasma membrane of astrocytes in the brain. As a result, osmotic gradients across cell membranes may be altered leading to water uptake by astrocytes and swelling. While a role for ROS has been proposed in mammals, no studies have addressed this question in …

Changes In Brain Water Content In The Rainbow Trout (Oncorhynchus Mykiss) And In The Goldfish (Carassius Auratus) Due To High External Ammonia Exposure, Phillip Q.H. Pham-Ho

Theses and Dissertations (Comprehensive)

In fishes, hyperammonemia may occur following feeding or exposure to abnormally high concentrations of environmental ammonia due to sewage effluents, agricultural run-off and in crowded aquaculture pens. Increased internal ammonia can result in hyperactivity, convulsions, coma and death. In mammals, it is also associated with potentially fatal brain edema, in which the accumulation of intracellular water results in swelling, increased intracranical pressure and herniation leading to death. Recently it was shown that rainbow trout (Oncorhynchus mykiss) and goldfish (Carassius auratus) experience brain swelling following exposure to high external ammonia (HEA). However, the mechanism of ammonia-induced brain …

Reactive Oxygen Species-Mediated Neurodegeneration Is Independent Of The Ryanodine Receptor In Caenorhabditis Elegans, Lyndsay E.A. Young, Daniel C. Williams

Journal of the South Carolina Academy of Science

Despite the significant impacts on human health caused by neurodegeneration, our understanding of the degeneration process is incomplete. The nematode Caenorhabditis elegans is emerging as a genetic model organism well suited for identification of conserved cellular mechanisms and molecular pathways of neurodegeneration. Studies in the worm have identified factors that contribute to neurodegeneration, including excitotoxicity and stress due to reactive oxygen species (ROS). Disruption of the gene unc-68, which encodes the ryanodine receptor, abolishes excitotoxic cell death, indicating a role for calcium (Ca²⁺) signaling in neurodegeneration. We tested the requirement for unc-68 in ROS-mediated neurodegeneration using the …

Characterizing The Rogfp2-Orp1 Fluorescent Biosensor For Detecting Oxidative Stress In Mammalian Cells, Sara A. Doan, Stevie Norcross, Mathew Tantama

The Summer Undergraduate Research Fellowship (SURF) Symposium

Parkinson’s disease is a neurodegenerative disease involving the death of neurons in the substantia nigra and loss of the neurotransmitter, dopamine. The disease leads to progressive loss of motor control. Exact causes and mechanisms by which Parkinson’s disease proceeds are unknown, however, previous experiments determine oxidative stress in mitochondria as a factor that results in cell death. Strategies have been implemented to generate fluorescent biosensors to monitor reactive oxygen species (ROS) concentrations while simultaneously measuring the spatiotemporal distribution and correlation between the ROS, cellular function and organelle. Orp1, an enzyme found in yeast, is a sensitive oxidizing species and when …

A Screen To Identify Saga-Activated Genes That Are Required For Proper Photoreceptor Axon Targeting In Drosophila Melanogaster, Kaelan J. Brennan, Vikki M. Weake, Jingqun Q. Ma

The Summer Undergraduate Research Fellowship (SURF) Symposium

The inherited human genetic disease spinocerebellar ataxia type 7 (SCA7) is characterized by progressive neurodegeneration and visual impairment that ultimately leads to blindness. SCA7 results from a mutation in the human ATXN7 gene that causes an expansion of polyglutamine tracts in this gene’s corresponding protein. Human ATXN7 protein serves as a component of the deubiquitylase (DUB) module of the large, multi-subunit complex Spt-Ada-Gcn acetyltransferase, or SAGA. SAGA is a transcriptional coactivator and histone modifier that functions to deubiquitylate histone H2B and allow for transcription of SAGA-mediated genes to occur. In Drosophila, mutations in SAGA DUB’s Nonstop and sgf11 components …

Structure And Composition Of Postsynaptic Densities, Madeline Farley

Dissertations and Theses (Open Access)

Communication between neurons within the brain occurs at chemical synapses and is fundamental for all brain functions. Modulation of the strength of communication is controlled by both presynaptic and postsynaptic mechanisms and is termed synaptic plasticity. One postsynaptic structure postulated to regulate synaptic strength is the postsynaptic density (PSD), a large electron dense protein complex located just below the synaptic membrane. The PSD, which is composed of signaling, scaffold and cytoskeletal proteins, supports and organizes neurotransmitter receptors within the synaptic membrane in addition to bridging signaling with the actin cytoskeletal network. The protein composition and structure of PSDs is known …

Susceptibility Of Parkinson’S Disease Following Mild Blast Traumatic Brain Injury, Glen Howel Galicia Acosta

Open Access Theses

Blast injury-induced neurotrauma (BINT) is steadily increasing in prevalence due to escalated terror activity and constitutes the signature injury associated with current military conflicts. BINT produces significant neurological deficiencies and there is a growing concern that the injury may produce long-term consequences that affect the resilience and the performance of soldiers. One of the potential consequences is an increased susceptibility to Parkinson's disease (PD). A vital goal aimed at curtailing the post-deployment long-term consequences of blast injury-induced neurotrauma is to further our knowledge of pathogenic mechanisms responsible for the escalation of post injury diseases. The purpose of this project is …

Evolutionary Convergence Of The Caffeine Biosynthetic Pathway In Chocolate Followed Duplication Of A Constrained Ancestral Enzyme, Andrew J. O'Donnell

Masters Theses

Caffeine biosynthesis is widely distributed in flowering plants and requires three consecutive methylation steps of xanthine alkaloids. Genes that have previously been reported to participate in the multi-step pathway in Coffea sp. (coffee) and Camellia sinensis (tea) encode members of the SABATH family of methyltransferases. Two genes highly expressed in fruits of Theobroma cacao (cacao) are orthologous to the caffeine genes in tea and appear to have diversified following gene duplication. Biochemical characterization of the enzymes (XMTs) encoded by these genes strongly suggest an unprecedented major pathway to theobromine, a precursor to caffeine. These findings imply that caffeine biosynthesis evolved …

Age-Dependent Breakdown Of The Blood Brain Barrier And Associated Changes In S100b Ko Mice, Eric V. Brown

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies play an important role in many autoimmune diseases. Recent research has shown that breakdown of the blood brain barrier (BBB) occurs concomitant to generation of brain reactive autoantibodies in many neurodegenerative diseases, which serve as biomarkers and drivers of pathology. SI00B, a calcium binding protein found most highly expressed in astrocytes which ensheathe the BBB, has many functions in neural development and signaling. Currently literature indicates that S100B KO mice develop normally, with no phenotypic abnormalities. Here, it is demonstrated that S100B KO mice seem to develop a chronic BBB breakdown similar to that seen in human neurodegenerative diseases. …

Efficient In Vitro Development Of Photoreceptors From Human Pluripotent Stem Cells, Joseph C. Reynolds

Dissertations, Masters Theses, Capstones, and Culminating Projects

Degeneration of the rod and cone photoreceptors in the human retina is among the most common causes of blindness. Replacing these damaged photoreceptors may help to restore vision. Repairing the damaged retina relies on the insertion of new, healthy cells. Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are two possible sources of photoreceptors to restore vision. Previous data shows that human ES cells and iPS cells can be differentiated into photoreceptors and transplanted into the eye to restore some vision. However, this process is inefficient, and costly. Here, we show a new method for inducing photoreceptor production …

The Effects Of Molecular Chaperones On Tau Fibril Assembly, Ahmed Omran

Electronic Theses and Dissertations

The accumulation of microtubule-associated protein tau into fibrillar aggregates is the hallmark of Alzheimer’s disease and other neurodegenerative disorders, collectively referred to as tauopathies. Fibrils can propagate from one cell to the next and spread throughout the brain. However, a study shows that only small aggregates can be taken up by cultured neuronal cells. The mechanisms that lead to the breakage of fibrils into smaller fragments remain unknown. In yeast, the AAA+ chaperone HSP104 processes the reactivation of protein aggregates and is responsible for fragmentation of fibrils. This study focused on investigating the effects of molecular chaperones on tau fibrils …

Pcdh19 Expression In Normal And Regenerating Adult Zebrafish Retinas, Kristin N. Forkapa Ms.

Williams Honors College, Honors Research Projects

My Honors Research Project will test the function of the N-cadherin molecule on the zebrafish optic nerve regeneration. N-cadherin is a member of the cadherin superfamily. Cadherins are cell adhesion molecules important for animal development and maintenance of adult structures. Unlike mammals, fish and amphibians have the ability to regenerate their optic nerve after damages. Molecular mechanisms underlying the optic nerve regeneration are still under intense investigation. Studies in Dr. Liu’s laboratory showed that expression of several cadherins, including N-cadherin, was greatly increased during adult zebrafish optic nerve regeneration, suggesting that cadherins may be involved in the optic nerve regeneration …

Nosh-Aspirin (Nbs-1120), A Dual Nitric Oxide And Hydrogen Sulfide-Releasing Hybrid, Reduces Inflammatory Pain, Miriam D. Fonseca, Fernando Q. Cunha, Khosrow Kashfi, Thiago M. Cunha

Publications and Research

The development of nitric oxide (NO)- and hydrogen sulfide (H2S)-releasing nonsteroidal anti-inflammatory drugs (NSAIDs) has generated more potent anti-inflammatory drugs with increased safety profiles. A new hybrid molecule incorporating both NO and H2S donors into aspirin (NOSH-aspirin) was recently developed. In the present study, the antinociceptive activity of this novel molecule was compared with aspirin in different models of inflammatory pain. It was found that NOSH-aspirin inhibits acetic acid-induced writhing response and carrageenan (Cg)-induced inflammatory hyperalgesia in a dosedependent (5–150 lmol/kg, v.o.) manner, which was superior to the effect of the same doses of aspirin. NOSH-aspirin’s antinociceptive effect was also …

Clique Topology Reveals Intrinsic Geometric Structure In Neural Correlations, Chad Giusti, Eva Pastalkova, Carina Curto, Vladimir Itskov

Department of Mathematics: Faculty Publications

Detecting meaningful structure in neural activity and connectivity data is challenging in the presence of hidden nonlinearities, where traditional eigenvalue-based methods may be misleading. We introduce a novel approach to matrix analysis, called clique topology, that extracts features of the data invariant under nonlinear monotone transformations. These features can be used to detect both random and geometric structure, and depend only on the relative ordering of matrix entries. We then analyzed the activity of pyramidal neurons in rat hippocampus, recorded while the animal was exploring a 2D environment, and confirmed that our method is able to detect geometric organization using …

Characterization Of The Trans-Plasma Membrane Electron Transport System In The Myelin Membrane, Afshan Sohail

Theses and Dissertations (Comprehensive)

Myelination is the key feature of evolution in the nervous system of vertebrates. Myelin is the protrusion of glial cells. More specifically, "oligodendrocytes" in the central nervous system (CNS), and "Schwann" cells in the peripheral nervous system (PNS) form myelin membranes. Myelin remarkably, enhances the propagation of nerve impulses. However, myelin restricts the access of extracellular metabolites to the axons. A pathology called "demyelination" is associated with myelin. The myelin sheath is not only an insulator, but it is itself metabolically active. In this study it is hypothesized that the ratio of NAD(P)⁺/NAD(P)H and the glycolytic pathway of …

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 …

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 …

Analysis Of Differential Mrna And Mirna Expression In An Alzheimer’S Disease Mouse Model, Amanda Hazy, Matthew Dalton

Other Undergraduate Scholarship

Research has shown that changes in gene expression play a critical role in the development of Alzheimer’s Disease (AD). Our project will evaluate genome-wide RNA expression patterns from brain and blood in an AD mouse model. This analysis will provide insight regarding the mechanisms of AD pathology as well as determine a possible diagnostic tool utilizing RNA expression patterns found in the blood as biomarkers for AD.

Large-Scale Identification Of Chemically Induced Mutations In Drosophila Melanogaster, Nele A Haelterman, Lichun Jiang, Yumei Li, Vafa Bayat, Hector Sandoval, Berrak Ugur, Kai Li Tan, Ke Zhang, Danqing Bei, Bo Xiong, Wu-Lin Charng, Theodore Busby, Adeel Jawaid, Gabriela David, Manish Jaiswal, Koen J T Venken, Shinya Yamamoto, Rui Chen, Hugo J Bellen

Faculty, Staff and Students Publications

Forward genetic screens using chemical mutagens have been successful in defining the function of thousands of genes in eukaryotic model organisms. The main drawback of this strategy is the time-consuming identification of the molecular lesions causative of the phenotypes of interest. With whole-genome sequencing (WGS), it is now possible to sequence hundreds of strains, but determining which mutations are causative among thousands of polymorphisms remains challenging. We have sequenced 394 mutant strains, generated in a chemical mutagenesis screen, for essential genes on the Drosophila X chromosome and describe strategies to reduce the number of candidate mutations from an average of …

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, …

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. …

Effects Of 5-Hydroxytryptamine 2c Receptor Agonist Mk212 And 2a Receptor Antagonist Mdl100907 On Maternal Behavior In Postpartum Female Rats, Weihai Chen, Qi Zhang, Wenxin Su, Yu Yang, Jing Qiao, Nan Sui, Ming Li

Department of Psychology: Faculty Publications

Maternal behavior in rats is a highly motivated and well-organized social behavior. Given the known roles of serotonin (5-HT) in emotion, motivation, social behavior, and major depression – and its known interaction with dopamine – it is likely that serotonin also plays a crucial role in this behavior. So far, there are surprisingly few studies focusing on 5-HT in maternal behavior, except for maternal aggression. In the present study,we examined the effects of 5-HT_2C receptor agonism and 5-HT_2A receptor antagonism on maternal behavior in postpartum female rats.We hypothesized that activation of 5-HT_2C receptors and blockade of 5-HT …

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 …

The Benefits Of Breastfeeding, Avery Kordus

Senior Honors Theses

Breastfeeding research is plentiful, and the majority of the literature shows that breast milk is the superior form of infant nutrition except in the rare circumstances of infant metabolic disorders, maternal drug use, or positive HIV status. In comparison to formula, breast milk provides improved cognition, development, behavior, bonding, nutrition, digestion, immunity, and long-term health with fewer diseases and conditions in infants. Mothers are benefited by breastfeeding through bonding, faster weight loss, and reduction in certain cancers and conditions. Breast milk contains the proper amount of carbohydrates, fats, proteins, vitamins, and minerals, and is also specialized for each infant and …

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 …

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 …

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 …

The Effects Of Chronic Simvastatin Treatment On The Expression Of Behavioral Symptoms In A Transgenic Mouse Model Of Huntington’S Disease, Ashley Whitmarsh

LSU New Orleans Theses and Dissertations

Huntington’s disease (HD) is a heritable, neurodegenerative disorder characterized by motor, cognitive, and psychiatric disturbances. An unstable CAG expansion within the gene normally encoding for the Huntingtin protein is responsible. The expanded mutant form of Huntingtin and the putative protein co-factor Rhes interact and cause cell death within the striatum. We hypothesized chronic treatment with simvastatin, a cholesterol lowering drug, would disrupt the biosynthetical pathway which gives both Rhes and its target cells binding sites and render Rhes inactive. Healthy and HD mice were treated with simvastatin or a vehicle. Animals’ motor behavior was assessed with three separate tests over …

From Gibbons To Gymnasts: A Look At The Biomechanics And Neurophysiology Of Brachiation In Gibbons And Its Human Rediscovery, Emma Et Pennock

Student Works

This conference paper serves to examine the evolutionary linkages of a brachiating ancestor in humans, the biomechanical and neurophysiology of modern day brachiators, and the human rediscovery of this form of locomotion. Brachiation is arguably one of the most metabolically effective modes of travel by any organism and can be observed most meritoriously in Gibbons. The purpose of the research conducted for this paper was to encourage further exploration of the neurophysiological similarities and differences between humans and non-human primates. The hope is that in spurring more interest and research in this area, further possibilities for rehabilitating brain injury will …

Effects Of Beta Amyloid On The Dna Methylation Status Of An In Vitro Model Of Alzheimer’S Disease, Noor Taher

Senior Honors Theses

Available evidence points toward an epigenetic process in Alzheimer’s disease. This thesis describes the research that was done to investigate changes in DNA methylation using an in vitro model of the disease. Although the results indicated no global changes in methylation levels after treating differentiated IMR-32 cells with beta amyloid, there were several regions of the genome that changed their methylation status. Gene ontology studies revealed that these regions are associated with neuronal differentiation and cell fate genes, thus providing a possible model for the contribution of beta amyloid to the development of Alzheimer’s disease. This study provides incentive to …