Neuroscience and Neurobiology Commons^™

Role Of The G Protein Beta Gamma Subunits In Serotonin Transporter Dynamics, Nora Awadallah

Dissertations, Theses, and Capstone Projects

Serotonin is a vital neurotransmitter and hormone with significant roles in almost every organ system. In the central nervous system, serotonin mediates physiological functions that in turn guide behavior and mood. Here, serotonin is released from serotonergic neurons and exerts its effects through serotonin receptors. Regulation of serotonin neurotransmission is important for the maintenance of its physiological functions; thus, extracellular serotonin must be sequestered to limit the intensity and duration of serotonin transmission. Disproportionate transmission is strongly linked with neurological and psychiatric ailments.

Extracellular serotonin levels are primarily mediated by the serotonin transporter (SERT), a critically important plasma membrane protein …

Role Of Nuclear Lamins In Oligodendrocyte Lineage Cells, Camila Yattah

Dissertations, Theses, and Capstone Projects

Differentiation of oligodendrocytes from progenitor cells is a highly regulated process characterized by a series of molecular changes, resulting in nuclear and morphological features unique to the mature oligodendrocyte state. Heterochromatin formation starting at the nuclear periphery, as well as increased nuclear rigidity are characteristically observed. The nuclear periphery is characterized by the presence of the nuclear lamina and it has been implicated in higher-order genome organization in cells. Lamins are the protein components of the nuclear lamina, and their expression is dependent upon the cell differentiation stage of the cells. While Lamin B1 (LMNB1) expression is high in progenitors …

Unexpected Arousal Suppresses Memory And Metamemory Predictions During Associative Face-Name Recognition Task, Sameer Sabharwal-Siddiqi

Dissertations, Theses, and Capstone Projects

Successful recognition often depends on probabilistic estimation of memory-signal. Arousal has been shown to offset the influence of heuristic evidence on memory prediction. We conducted three experiments that tested whether arousal also suppresses predictions relevant to memory confidence. Experiments employed associative face-name memory tasks that included retrospective (Experiments 1 and 2) or concurrent (Experiment 3) judgements of confidence. During test, subjects were presented with a masked-affective face on a subset of trials. By timing the masked-affective face to precede a recognition judgement (Experiment 1), we replicated the finding that unexpected arousal offsets the influence of heuristic evidence on expectations of …

Clustered Protocadherins Ubiquitination And Phosphorylation Regulates Surface Expression, Albert Ptashnik

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) are a family of 60 adhesion-like molecules forming a neural barcode. In vertebrate neurons, 60 Pcdhs are coded by a large gene cluster. Numerous axons in the cluster are coding for the different extracellular, transmembrane, variable portion of the cytoplasmic and constant cytoplasmic domains where their expression is controlled epigenetically. These proteins mediate interactions between axons, dendrites, and glial cells during neural development. Yet, Pcdhs are not strictly adhesion molecules. In the amacrine cells of the retina, Pcdhs promote avoidance of the same cell dendrites, where in the cortex Pcdhs promote interactions between dendrites and astrocytes. In …

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 …

Transcriptional Mechanisms Of Neuroprotection In Excitotoxicity Driven Neurodegeneration In C. Elegans, Zelda Z. Mendelowitz

Dissertations, Theses, and Capstone Projects

Excitotoxicity is notorious for triggering neuronal cell death in both developmental and adult-onset neurodegenerative diseases. In excitotoxicity, excessive concentrations of Glutamate in the synapse overstimulate Glutamate Receptors (GluRs) on postsynaptic neurons. While GluR mediated degenerative mechanisms remain obscure, GluR activation was surprisingly found to also have a neuroprotective effect through activation of specific transcriptional programs. To identify evolutionarily conserved transcriptional programs in neuroprotection we use a C. elegans model of excitotoxic necrosis (glt-3;nuIs5). We have identified that non-canonical activation of the transcription factor CRH-1/CREB mediates neuroprotection in our excitotoxicity model. We found the Histone Acetyl Transferase, MYS-1/KAT6, and the neuronal …

Sensorimotor Content Of Multi-Unit Activity In The Paramedian Lobule Of The Cerebellum, Esma Cetinkaya

Dissertations

Based on Center for Disease Control and Prevention report 2016, around 39.5 million people in the United States suffer from motor disabilities. These disabilities are due to traumatic conditions like traumatic brain injury (TBI), neurological diseases such as amyotrophic lateral sclerosis (ALS), or congenital conditions. One of the approaches for restoring the lost motor function is to extract the volitional information from the central nervous system (CNS) and control a mechanical device that can replace the function of a paralyzed limb through systems called Brain-Computer Interfaces (BCI).

One of the major challenges being faced in BCIs and also in general …

Development And Evaluation Of A Hand Exoskeleton For Neurorehabilitation Post Stroke, Ashley Joyce Mont

Dissertations

Stroke affects approximately 800,000 people in the United States each year, and due to its chronic effects, it is one of the leading causes of disability. Many individuals with stroke suffer the loss of motor function in their paretic upper extremity, and longitudinal studies show that 30 — 66% of individuals with hemiplegia fail to regain arm function six months post stroke. After a stroke, the brain undergoes neuroplasticity which will promote recovery of function. Investigators and clinicians are trying to develop rehabilitation interventions that can be designed to promote neuroplasticity, enhancing the recovery outcomes of therapy.

For individuals with …

Investigating The Role Of The Transcriptional Coregulator Cited2 In Regulating Intermediate Progenitor Proliferation And Modulating Behavior, Nikolaus R. Wagner

Dissertations - ALL

The mammalian neocortex develops from a thin layer of neuroepithelial cells into a robust mosaic of differentiated neurons organized into distinct layers and functional areas. This process requires a complex choreography of transcription factors and epigenetic regulators to be spatially and temporally activated in a precise manner. Disruptions in any aspect of this delicate process may lead to neurodevelopmental disorders like autism spectrum disorder, schizophrenia, or intellectual disability. One such transcriptional coregulator that is a crucial regulator of neocortical development is Cited2. Previous work demonstrated that forebrain-specific Cited2 loss-of-function causes a reduction in neocortical progenitor proliferation which leads to reduced …

Role Of Nucleobindin-2/Nesfatin-1 In The Regulation Of Energetic Status And Maternal Mouthbrooding In The Cichlid Fish, Astatotilapia Burtoni, Saachi Chugh

LSU Master's Theses

Feeding and energetics are fundamental processes in all species that must also be balanced with reproductive investment. The peptide hormone nesfatin-1 is encoded by the nucleobindin-2(nucb2) gene and has recently emerged as a key player involved in both feeding and reproduction across vertebrates. How nesfatin-1 might help regulate trade-offs between feeding and reproduction, however, are relatively unexplored. The female cichlid fish Astatotilapia burtoniis an ideal system to examine the role of nesfatin-1 in regulating metabolic and reproductive functions because this species cycles between a gravid feeding state while preparing to mate, followed by a forced starvation …

Explicit And Implicit Emotion Processing In The Cerebellum: A Meta‑Analysis And Systematic Review, Jordan E. Pierce, Marine Thomasson, Philippe Voruz, Garance Selosse, Julie Péron

Center for Brain, Biology, and Behavior: Faculty Publications

The cerebellum’s role in affective processing is increasingly recognized in the literature, but remains poorly understood, despite abundant clinical evidence for affective disruptions following cerebellar damage. To improve the characterization of emotion processing and investigate how attention allocation impacts this processing, we conducted a meta-analysis on task activation foci using GingerALE software. Eighty human neuroimaging studies of emotion including 2761 participants identified through Web of Science and ProQuest databases were analyzed collectively and then divided into two categories based on the focus of attention during the task: explicit or implicit emotion processing. The results examining the explicit emotion tasks identified …

Roundup And Glyphosate’S Impact On Gaba To Elicit Extended Proconvulsant Behavior In Caenorhabditis Elegans, Akshay Naraine, Rebecca Aker, Isis Sweeney, Meghan Kalvey, Alexis Surtel, Venkatesh Shanbhag, Ken Dawson-Scully

Chemistry and Physics Faculty Articles

As 3 billion pounds of herbicides are sprayed over farmlands every year, it is essential to advance our understanding how pesticides may influence neurological health and physiology of both humans and other animals. Studies are often one-dimensional as the majority examine glyphosate by itself. Farmers and the public use commercial products, like Roundup, containing a myriad of chemicals in addition to glyphosate. Currently, there are no neurological targets proposed for glyphosate and little comparison to Roundup. To investigate this, we compared how glyphosate and Roundup affect convulsant behavior in C. elegans and found that glyphosate and Roundup increased seizure-like behavior. …

Axonal Architecture Of The Mouse Inner Retina Revealed By Second Harmonic Generation, Arafat Meah, Vinessia Boodram, Festa Bucinca-Cupallari, Hyungsik Lim

Publications and Research

We describe a novel method for visualizing the network of axons in the unlabeled fresh wholemount retina. The intrinsic radiation of second harmonic generation (SHG) was utilized to visualize single axons of all major retinal neurons, i.e., photoreceptors, horizontal cells, bipolar cells, amacrine cells, and the retinal ganglion cells. The cell types of SHG + axons were determined using transgenic GFP/YFP mice. New findings were obtained with retinal SHG imaging: Müller cells do not maintain uniformly polarized microtubules in the processes; SHG + axons of bipolar cells terminate in the inner plexiform layer (IPL) in a subtype-specific manner; a subset …

The Effects Of A Multi-Ingredient Supplement On Various Cognitive Measures, Jason M. Curtis, Cassandra Evans, Veronica Mekhail, Paulina Czartoryski, Juan Carlos Santana, Jose Antonio

Journal for Sports Neuroscience

The purpose of this study was to investigate the effects of a multi-ingredient pre-workout supplement (MIPS) on mental and physical performance. Seventeen exercise-trained men (n = 7) and women (n=10) completed this randomized, placebo-controlled, double-blind, counterbalanced, crossover trial. Participants consumed either a multi-ingredient pre-workout supplement (MIPS) or a placebo in a randomized, counterbalanced order. Forty-five minutes post-consumption, the following assessments were conducted: psychomotor vigilance test (PVT), Profile of Mood States (POMS), Stroop test, vertical jump test, and a Cold pressor test. There was a one-week washout period between assessments. There were significant differences in the incongruent task for the Stroop …

Noninvasive Neuromodulation Via Ultrasonic Activation Of Endogenous And Exogenous Ion Channels, Yaoheng Yang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neuromodulation technology is key to understanding brain function and treating brain diseases. Conventional neuromodulation technologies, such as direct current stimulation, transcranial magnetic stimulation, and optogenetics, predominately rely on electromagnetic waves. However, the fundamental physical law  the tradeoff-relationship between penetration and spatial resolution, limits their transcranial penetration within the superficial cortex layer. To overcome this challenge, electrodes or optical fibers need to be surgically implanted into the brain to modulate specific brain regions. Different from electromagnetic waves, ultrasound, as a mechanical wave, can non-invasively penetrate through the intact skull to reach deep brain regions with millimeter spatial focus. Ultrasound has …

Development Of Noninvasive Biomarkers For Cervical Spondylotic Myelopathy, Dinal Jayasekera

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cervical spondylotic myelopathy (CSM) represents the most common cause of chronic spinal cord injury (SCI) in adults. Many patients with symptomatic CSM will experience a decline in neurological function and consequently undergo surgical decompression. Unfortunately, surgeons are unable to adequately counsel patients about the benefits of surgery because the natural history of disease and outcome after decompression vary widely among patients. This can hinder the decision-making capacity of patients and physicians. Therefore, we require additional tools to help guide therapy and counsel patients with CSM. Noninvasive biomarkers present valuable potential as predictors of a patient’s recovery in the long term. …

Mechanisms Of Primate Working Memory, Charles Damian Holmes

McKelvey School of Engineering Graduate Student Theses & Dissertations

One of the defining features of the behavior of many animal species is the ability to retain and utilize information from the environment even after it is gone. The encoding and utilization of information on short time scales is referred to as working memory. It is not yet fully understood how the brain accomplishes working memory.

This dissertation presents three studies that help to characterize the working memory system of primates. All three studies involve primates performing saccades during a spatial memory task. The first study demonstrates that while the local field potential power is contralaterally tuned (i.e., power is …

Neural Stem Cells: Age-Dependent Outcomes During Viral Infections In The Central Nervous System, Manisha N. Chandwani

Electronic Theses and Dissertations

Viral infections in the central nervous system (CNS) are associated with neurodevelopmental and neurobehavioral deficits. The outcomes of viral infections can be driven by damage and death of neurons. Neural stem cells (NSCs) play key roles in neurodevelopment, repair, and physiological brain function. During a viral infection, NSC activity can disturbed by direct infection of NSCs by the virus or by anti-viral immune response. Here, we aimed to assess whether the anti-viral immune response can impact NSC activity during an immunocompetent response in the adult brain. We utilized a transgenic mouse model of Measles virus infection where only the CNS …

Aberrant Age-Related Alterations In Spontaneous Cortical Activity In Participants With Cerebral Palsy, Hannah Bergwell

Theses & Dissertations

Cerebral Palsy (CP) is the most common neurodevelopmental motor disability, resulting in life-long sensory, perception and motor impairments. These impairments appear to drastically worsen with advancing age within the CP population, although the underlying neuro-physiological mechanisms remain poorly understood. Herein, we began to address this knowledge gap by utilizing magnetoencephalographic (MEG) to study how aging impacts the amplitude of spontaneous brain activity (i.e., resting state) in a cohort of 38 individuals with spastic diplegic CP (Age = 22.08 ± 10.46 years) and 67 neurotypical controls (NT) (Age = 19.56 ± 10.25 years). Participants completed an eyes-closed resting-state paradigm while undergoing …

Impacts On Fast-Start Performance: How Do Group Size And Habitat Degradation Alter The Escape Behavior Of A Schooling Coral Reef Fish?, Monica D. Bacchus

All HCAS Student Capstones, Theses, and Dissertations

Escaping predation is essential for species survival, but prey must effectively match their response to the perceived threat imposed by a predator. Fish evaluate their surroundings using several sensory stimuli, including olfactory, visual, auditory, and mechanical cues. A range of taxa use the fast-start response to evade predators, including fishes, sharks, and larval amphibians. While the fast-start response (rapid bursts of swimming) is extensively studied in solitary fishes, the factors that mediate the collective escape response in schools of fish have historically been investigated far less. To address this knowledge gap, the collective escape behavior and individual escape performance of …