Neuroscience and Neurobiology Commons^™

Dopaminergic Innervation Of The Subventricular Zone In The Murine Brain, Linda Beth Drozdowicz

Honors Scholar Theses

The subventricular zone (SVZ) is one of two areas in the brain that, in a healthy mouse, continually generate neurons throughout adulthood. While it was previously thought that only the A9 neurons of the substantia nigra sent dopaminergic afferents to the SVZ, recent studies suggest that the A10 neurons of the ventral tegmental area may innervate this area. This project has aimed to discover which, if either, model is correct.

Examination of the Aphakia (AK) mouse was used to determine the role of distinct midbrain regions in SVZ regulation. Additionally, intraperitoneal injections of the chemical MPTP were used to deduce …

Effect Of Visual Input On Vowel Production In English Speakers, Amanda C. Richardson

Linguistics Honors Projects

This study analyzes whether there should be a visual component to a model of speech perception and production by comparing the jaw opening, advancement, and rounding of American English and non-English vowels in the presence and absence of a visual stimulus. Surprisingly, jaw opening did not change production, but the presence of the visual stimulus was found to be a significant factor in participants’ vowel advancement for non-English vowels. This may be explained by lip rounding, but requires further research in order to develop a full understanding of the impact of visual input on vowel production to be used in …

Targeting Fatty Acid-Activated Pathways In The Somatosensory System, Tian Yu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Given the dramatic rise in obesity and the diseases linked with it, it is becoming increasingly important to understand the mechanisms that underlie the body's ability to recognize fat. The chemoreception of dietary fat in the oral cavity has largely been attributed to activation of the somatosensory system that relays the textural properties of fat. However, the ability of fatty acids, which are believed to represent the proximate stimulus for fat taste, to activate trigeminal ganglionic neurons has remained unexplored. In general, my research has provided the first evidence of fatty acids activating the somatosensory system by increasing the intracellular …

A Longitudinal Study Of Neurocognitive Deficits And Functional Outcome In Bipolar Disorder, Brian D. Leany

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar disorder is an affective disorder that, in addition to being characterized by depressive and expansive mood symptoms, often presents with neuropsychological deficits. Bipolar disorder not only impairs an individual’s cognitive abilities, but these cognitive impairments may also impact day-to-day activities causing functional impairment. In other psychiatric disorders such as schizophrenia, it has been shown that the neuropsychological deficits are predictive of poor, long term treatment outcome and functioning. However, while bipolar disorder affects nearly 1 - 2% of the U.S. population (Keck, McElroy, & Arnold, 2001), little is known about the extent that neurocognitive deficits may play in the …

Damage-Induced Inflammation And Nociceptive Hypersensitivity In Drosophila Larvae, Daniel T. Babcock

Dissertations and Theses (Open Access)

Mounting an effective response to tissue damage requires a concerted effort from a number of systems, including both the immune and nervous systems. Immune-responsive blood cells fight infection and clear debris from damaged tissues, and specialized pain receptors become hypersensitive to promote behavior that protects the damaged area while it heals. To uncover the cellular and molecular mechanisms underlying these processes, we have developed a genetically tractable invertebrate model of damage-induced inflammation and pain hypersensitivity using Drosophila larvae.

To study wound-induced inflammation, we generated transgenic larvae with fluorescent epidermal cells and blood cells (hemocytes). Using live imaging, we monitored the …

Role Of Dopamine Of Nucleus Accumbens In Behavioral Sensitization To Methylphenidate, Sheshali J. Wanchoo

Dissertations and Theses (Open Access)

Behavioral sensitization is defined as the subsequent augmentation of the locomotor response to a drug following repeated administrations of the drug. It is believed to occur due to alterations in the motive circuit in the brain by stressors, central nervous system stimulants, and similar stimuli. The motive circuit (or mesocorticolimbic system) consists of several interconnected nuclei that determine the behavioral response to significant biological stimuli. A final target of the mesocorticolimbic system is the nucleus accumbens (NAc), which is a key structure linking motivation and action. In particular, the dopaminergic innervations of the Nac are considered to be essential in …

Signaling Mechanisms That Control Gap Junctional Coupling Between Retinal Neurons, Wade Kothmann

Dissertations and Theses (Open Access)

Gap junctions between neurons form the structural substrate for electrical synapses. Connexin 36 (Cx36, and its non-mammalian ortholog connexin 35) is the major neuronal gap junction protein in the central nervous system (CNS), and contributes to several important neuronal functions including neuronal synchronization, signal averaging, network oscillations, and motor learning. Connexin 36 is strongly expressed in the retina, where it is an obligatory component of the high-sensitivity rod photoreceptor pathway. A fundamental requirement of the retina is to adapt to broadly varying inputs in order to maintain a dynamic range of signaling output. Modulation of the strength of electrical coupling …

Eye Movement Measures Of Cognitive Control In Children With To Urette Syndrome, Cameron B. Jeter

Dissertations and Theses (Open Access)

Tourette Syndrome begins in childhood and is characterized by uncontrollable repetitive actions like neck craning or hopping and noises such as sniffing or chirping. Worst in early adolescence, these tics wax and wane in severity and occur in bouts unpredictably, often drawing unwanted attention from bystanders. Making matters worse, over half of children with Tourette Syndrome also suffer from comorbid, or concurrent, disorders such as attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). These disorders introduce anxious thoughts, impulsivity, inattention, and mood variability that further disrupt children with Tourette Syndrome from focusing and performing well at school and home. …

The Expression And Cellular Localization Of Cc-Chemokine Receptor 5 (Ccr5) After Traumatic Brain Injury, Vuvi H. Nguyen

Dissertations and Theses (Open Access)

Traumatic brain injury results from a primary insult and secondary events that together result in tissue injury. This primary injury occurs at the moment of impact and damage can include scalp laceration, skull fraction, cerebral contusions and lacerations as well as intracranial hemorrhage. Following the initial insult, a delayed response occurs and is characterized by hypoxia, ischemia, cerebral edema, and infection. During secondary brain injury, a series of neuroinflammatory events are triggered that can produce additional damage but may also help to protect nervous tissue from invading pathogens and help to repair the damaged tissue. Brain microglia and astrocytes become …

Protein-Protein Interactions That Regulate Neurotransmitter Release From Retinal Ribbon Synapses, (Leigh) Beth T. Latham

Dissertations and Theses (Open Access)

Protein-Protein Interactions That Regulate Neurotransmitter Release from Retinal Ribbon Synapses Photoreceptors and bipolar cells in the retina form specialized chemical synapses called ribbon synapses. This type of synapse differs physiologically from “conventional” chemical synapses. While “conventional” synapses exocytose neurotransmitter-filled vesicles in an all-or-none fashion in response to an action potential, a retinal ribbon synapse can release neurotransmitter tonically (sustained) in response to graded changes in membrane potential or phasically (transient) in response to a large change in membrane potential.

Synaptic vesicle exocytosis is a tightly controlled process involving many protein-protein interactions. Therefore, it is likely that the dissimilarity in the …

The Expression And Cellular Localization Of Cc-Chemokine Receptor 5 (Ccr5) After Traumatic Brain Injury, Vuvi H. Nguyen

Dissertations and Theses (Open Access)

Traumatic brain injury results from a primary insult and secondary events that together result in tissue injury. This primary injury occurs at the moment of impact and damage can include scalp laceration, skull fraction, cerebral contusions and lacerations as well as intracranial hemorrhage. Following the initial insult, a delayed response occurs and is characterized by hypoxia, ischemia, cerebral edema, and infection. During secondary brain injury, a series of neuroinflammatory events are triggered that can produce additional damage but may also help to protect nervous tissue from invading pathogens and help to repair the damaged tissue. Brain microglia and astrocytes become …

Developmental Changes In The Structure And Composition Of The Postsynaptic Density, Matthew T. Swulius

Dissertations and Theses (Open Access)

The development of the brain and its underlying circuitry is dependent on the formation of trillions of chemical synapses, which are highly specialized contacts that regulate the flow of information from one neuron to the next. It is through these synaptic connections that neurons wire together into networks capable of performing specific tasks, and activity-dependent changes in their structural and physiological state is one way that the brain is thought to adapt and store information. At the ultrastructural level, developmental and activity-dependent changes in the size and shape of dendritic spines have been well documented, and it is widely believed …

Genes Involved In Mushroom Body Development And Behavior In Drosophila, Christine Nicole Serway

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mushroom bodies (MBs) are the site of multi modal sensory integration critical for associative conditioning in Drosophila. They have been central to research on the structure function relationship in the brain for over one hundred years due to their unique shape and readily accessible physiology. This dissertation incorporates three different approaches to further elucidate the genetic and molecular nature of this structure function relationship.

First, the suite of genetic and molecular tools available in Drosophila melanogaster, facilitated the molecular mapping of a 25-year old MB structural mutant called mushroom body miniature B (mbmB) to the gene Pendulin [Pen, also known …

Neuronbank: A Tool For Cataloging Neuronal Circuitry, Paul S. Katz, Robert Calin-Jageman, Akshaye Dhawan, Chad Frederick, Shuman Guo, Rasanjalee Dissanayaka, Naveen Hiremath, Wenjun Ma, Xiuyn Shen, Hsui C. Wang, Hong Yang, Sushil Prasad, Rajshekhar Sunderraman, Ying Zhu

Mathematics, Computer Science & Statistics Faculty Publications

The basic unit of any nervous system is the neuron. Therefore, understanding the operation of nervous systems ultimately requires an inventory of their constituent neurons and synaptic connectivity, which form neural circuits. The presence of uniquely identifiable neurons or classes of neurons in many invertebrates has facilitated the construction of cellular-level connectivity diagrams that can be generalized across individuals within a species. Homologous neurons can also be recognized across species. Here we describe NeuronBank.org, a web-based tool that we are developing for cataloging, searching, and analyzing neuronal circuitry within and across species. Information from a single species is represented in …

The Effects Of Handedness And Bilateral Saccadic Eye Movements On False Alarms In Recognition Memory, Lisa Weinberg

Psychology Honors Projects

Handedness can be used as a marker for interhemispheric interaction, which can produce memory benefits. Bilateral saccadic eye movements can be used to manipulate levels of interhemispheric interaction. This study measured the effects of handedness and bilateral saccadic eye movement on memory using the Deese-Roediger-McDermott paradigm. This study predicted a memory advantage for left-handers and mixed-handers without eye movements and an advantage for right-handers with the eye movements. The results do not support these predictions but do suggest that handedness is a factor in episodic memory performance. The analyses for this study were run using A’ to compare false alarm …

12-Month-Olds’ Discrimination Of Monkey Faces: Evidence For Perceptual Narrowing?, Jacob C. Jones, Scott Stevens, Melissa Wright, Amanda Phillippi

FHSS Mentored Research Conference

It is well known from birth that faces are salient, preferred over other stimuli, and are readily discriminated. It has also been shown that over the course of development infants’ proclivity for face discrimination is influenced by their social environment. Pascalis, deHann, andNelson (2002), for example, demonstrate that 6-month-olds are able to discriminate various monkey faces as well as human faces whereas 9-month-olds can only discriminate different human faces. Importantly, however, if 6-month-olds receive 1-2 minutes per day of familiarization with photographs of monkey faces three months later the now 9-month-olds can still discriminate unfamiliar and familiar monkey faces. Like …

Group Ii Metabolic Glutamate Receptors In The Basal Amygdala Regulate Sleep And Fear-Induced Alterations In Sleep, Enheng Dong

Theses and Dissertations in Biomedical Sciences

Glutamate is a major excitatory neurotransmitter in the brain and it has been recognized as playing an essential role in activating and maintaining arousal. Group II metabotropic glutamate (mGlu II) receptors are expressed in the amygdala, a brain structure important in the regulation of stress and anxiety as well as in the regulation of sleep and arousal. Our lab has found that the central nucleus of the amygdala (CNA) is involved in the emotional modulation of sleep. The basal amygdala (BA), which has direct connections with the CNA, is involved in conditioned fear and fear extinction. However, the potential role …

Decreasing Temperature Below Tt Or Increasing Cholesterol Enhance Vesibcle-Bilayer Membrane Fusion, David E. Lee, Reed A. Doxey, Kevin J. Tuttle, Dixon J. Woodbury

FHSS Mentored Research Conference

Lipid composition plays an important role in fusion of vesicles to membranes, an essential process for exocytosis. Lipid head group, tail structure, and sterol content all impact the complex phase behavior of membranes. To determine the effect of lipids on fusion, we utilized the nystatin/ergesterol (nys/erg) fusion assay and stimulated fusion with a salt (osmotic) gradient. With this assay, vesicles containing nys and erg fuse with a planar membrane producing characteristic spike increases in membrane conductance.Using PE/PC (7:3) membranes, we varied cholesterol from 0-40 mol% and observed significant increases in fusion rates. In one series of experiments, membranes were formed …

Cellular Immunity In Mouse Models Of Viral Encephalitis, Christina Dawn Steel

Theses and Dissertations in Biomedical Sciences

Evidence is presented herein that intranasal application of vesicular stomatitis virus (VSV) caused acute infection of the murine central nervous system (CNS) with associated morbidity and significant mortality in mice. However, VSV encephalitis was not invariably fatal, suggesting that the CNS contained a professional antigen-presenting cell (APC) capable of inducing or propagating a protective antiviral immune response. To examine this possibility, we administered VSV via the intranasal route and then characterized the cellular elements that infiltrate the brain as well as the activation status of resident microglia, cells widely believed to represent the major APC population in the CNS. To …

Locus Of Control And The Age Difference In Free Recall From Episodic Memory, Paul Amrhein, Judith K. Bond, Derek Hamilton

Department of Psychology Faculty Scholarship and Creative Works

The authors investigated the relation of locus of control (LOC) to age differences in free-recall memory performance. Older and younger participants completed P. C. Duttweiler's (1984) Internal Control Index (ICI) and subsequently performed free-recall memory tasks. Compared with the younger participants, the older participants exhibited poorer recall with more intrusions and uncorrected repetition errors as well as reduced categorical clustering. For the older participants with less internal LOC, recall proportion and item-pair associative recall clustering were lower than for the older participants with more internal LOC. By contrast, the younger participants did not exhibit any LOC effects in their recall …

Seasonal Hippocampal Plasticity In Food-Storing Birds., David F Sherry, Jennifer S Hoshooley

Psychology Publications

Both food-storing behaviour and the hippocampus change annually in food-storing birds. Food storing increases substantially in autumn and winter in chickadees and tits, jays and nutcrackers and nuthatches. The total size of the chickadee hippocampus increases in autumn and winter as does the rate of hippocampal neurogenesis. The hippocampus is necessary for accurate cache retrieval in food-storing birds and is much larger in food-storing birds than in non-storing passerines. It therefore seems probable that seasonal change in caching and seasonal change in the hippocampus are causally related. The peak in recruitment of new neurons into the hippocampus occurs before birds …

Differential Activation Of Frontoparietal Attention Networks By Social And Symbolic Spatial Cues, Andrew D. Engell, Lauri Nummenmaa, Nikolaas N. Oosterhof, Richard N. Henson, James V. Haxby, Andrew J. Calder

Dartmouth Scholarship

Perception of both gaze-direction and symbolic directional cues (e.g. arrows) orient an observer’s attention toward the indicated location. It is unclear, however, whether these similar behavioral effects are examples of the same attentional phenomenon and, therefore, subserved by the same neural substrate. It has been proposed that gaze, given its evolutionary significance, constitutes a ‘special’ category of spatial cue. As such, it is predicted that the neural systems supporting spatial reorienting will be different for gaze than for non-biological symbols. We tested this prediction using functional magnetic resonance imaging to measure the brain’s response during target localization in which laterally …

Dopamine Neuron Stimulating Actions Of A Gdnf Propeptide, Luke H. Bradley, Josh Fuqua, April Richardson, Jadwiga Turchan-Cholewo, Yi Ai, Kristen A. Kelps, John D. Glass, Xiuquan He, Zhiming Zhang, Richard Grondin, O. Meagan Littrell, Peter Huettl, Francois Pomerleau, Don M. Gash, Greg A. Gerhardt

Neuroscience Faculty Publications

BACKGROUND: Neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF), have shown great promise for protection and restoration of damaged or dying dopamine neurons in animal models and in some Parkinson's disease (PD) clinical trials. However, the delivery of neurotrophic factors to the brain is difficult due to their large size and poor bio-distribution. In addition, developing more efficacious trophic factors is hampered by the difficulty of synthesis and structural modification. Small molecules with neurotrophic actions that are easy to synthesize and modify to improve bioavailability are needed.

METHODS AND FINDINGS: Here we present the neurobiological actions of dopamine …

The Cost Of Treating Posttraumatic Stress Disorder And Mild Traumatic Brain Injuries, Amy L. Gilliland

Theses and Dissertations

Mild Traumatic Brain Injuries (mTBIs) and Post Traumatic Stress Disorder (PTSD) are two of the signature wounds of war. Due to the advances in technology the survival rates are higher than in previous wars, however, the weaponry has changed. The world has seen an increase in the use of suicide bombs, improvised explosive devices (IEDs) and rocket propelled grenades (RPGs) which increases the number of blast related injuries. One of the major problems with blast related injuries is that they can be invisible to the naked eye. The lack of physical evidence suggests the soldier is not injured and can …

Efficient Encoding Of Vocalizations In The Auditory Midbrain, Lars Andreas Holmstrom

Systems Science Friday Noon Seminar Series

An important question in sensory neuroscience is what coding strategies and mechanisms are used by the brain to detect and discriminate among behaviorally relevant stimuli. To address the noisy response properties of individual neurons, sensory systems often utilize broadly tuned neurons with overlapping receptive fields at the system's periphery, resulting in homogeneous responses among neighboring populations of neurons. It has been hypothesized that progressive response heterogeneity in ascending sensory pathways is evidence of an efficient encoding strategy that minimizes the redundancy of the peripheral neural code and maximizes information throughput for higher level processing. This hypothesis has been partly supported …

Behind The Mask: The Influence Of Mask-Type On Amygdala Response To Fearful Faces, M Justin Kim, Rebecca A. Loucks, Maital Neta, F. Caroline Davis, Jonathan A. Oler, Emily C. Mazzulla, Paul J. Whalen

Dartmouth Scholarship

In this study, we compared the effects of using neutral face masks vs non-face pattern masks on amygdala activity to masked fearful faces. Twenty-seven subjects viewed 18 s blocks of either fearful or happy faces masked with either neutral faces or patterns, while their brain activity was measured using functional magnetic resonance imaging. Results replicated increased amygdala activation to face-masked fearful vs happy faces. In the pattern mask condition, the amygdala discriminated between masked fearful and happy faces, but this effect manifested as a decrease in activation to fearful faces compared to happy faces. This interactive effect between facial expression …

Effects Of Socioeconomic Status On Brain Development, And How Cognitive Neuroscience May Contribute To Levelling The Playing Field, Rajeev Raizada, Mark M. Kishiyama

Dartmouth Scholarship

The study of socioeconomic status (SES) and the brain finds itself in a circumstance unusual for Cognitive Neuroscience: large numbers of questions with both practical and scientific importance exist, but they are currently under-researched and ripe for investigation. This review aims to highlight these questions, to outline their potential significance, and to suggest routes by which they might be approached. Although remarkably few neural studies have been carried out so far, there exists a large literature of previous behavioural work. This behavioural research provides an invaluable guide for future neuroimaging work, but also poses an important challenge for it: how …

A Novel Choline Cotransporter Sequestration Compartment In Cholinergic Neurons Revealed By Selective Endosomal Ablation, Michael T. Ivy, Robert F. Newkirk, Yilun Wang, James G. Townsel

Biology Faculty Research

The sodium-dependent, high affinity choline transporter – choline cotransporter – (ChCoT, aka: cho-1, CHT1, CHT) undergoes constitutive and regulated trafficking between the plasma membrane and cytoplasmic compartments. The pathways and regulatory mechanisms of this trafficking are not well understood. We report herein studies involving selective endosomal ablation to further our understanding of the trafficking of the ChCoT. Selective ablation of early sorting and recycling endosomes resulted in a decrease of ∼75% of [3H]choline uptake and ∼70% of [3H]hemicholinium-3 binding. Western blot analysis showed that ablation produced a similar decrease in ChCoTs in the plasma membrane subcellular fraction. The time frame …

Bilateral Multi-Electrode Neurophysiological Recordings Coupled To Local Pharmacology In Awake Songbirds, Liisa A. Tremere, Thomas A. Terleph, Jin Kwon Jeong, Raphael Pinaud

Biology Faculty Publications

Here we describe a protocol for bilateral multielectrode neurophysiological recordings during intracerebral pharmacological manipulations in awake songbirds. This protocol encompasses fitting adult animals with head-posts and recording chambers, and acclimating them to periods of restraint. The adaptation period is followed by bilateral penetrations of multiple electrodes to obtain acute, sensory-driven neurophysiological responses before versus during the application of pharmacological agents of interest. These local manipulations are achieved by simultaneous and restricted drug infusions carried out independently for each hemisphere. We have used this protocol to elucidate how neurotransmitter and neuroendocrine systems shape the auditory and perceptual processing of natural, learned …

Effects Of Chlordiazepoxide On Predator Odor-Induced Reductions Of Playfulness In Juvenile Rats, Stephen M. Siviy, Courtney L. Steets, Lauren M. Debrouse

Psychology Faculty Publications

The extent to which a non-sedative dose of chlordiazepoxide (CDP) is able to modify the behavioral responses toward a predator odor was assessed in juvenile rats. Play behavior was suppressed and defensive behaviors were enhanced in the presence of a collar previously worn by a cat, when tested 24 hours later in the same context as that where the exposure occurred, and when tested in a context different than that in which the exposure occurred for up to 3 hours after exposure. CDP had no effect on the ability of cat odor to suppress play when rats were tested in …