Biology Commons^™

Functions Of Fibroblast Growth Factor Homologous Factor 2 In Excitable Tissues, Christopher Marra

Dissertations, Theses, and Capstone Projects

Purpose: Fibroblast Growth Factor Homologous Factors (FHFs) are a group of proteins known to associate with and modulate voltage-gated sodium channels (Na_v) in excitable cells. The four FHF genes are differentially expressed in specific cell-types, with FHF2 expressed prominently in the hippocampus, cerebral cortex, heart and dorsal root ganglia. Due to previous unavailability of an Fhf2 knockout mouse, this gene’s functions have been understudied in comparison to other those encoding other FHFs. The purpose of this research has been to better understand the normal physiological functions of FHF2 at the cellular and system levels in the heart, sensory …

Employing High Probability Gene Choice Elements To Understand Singular Odorant Receptor Expression, Raena Mina

Dissertations, Theses, and Capstone Projects

The ability to detect odorous chemicals in the environment is the oldest of the senses necessary for survival, from escaping danger, finding mates, to locating food. It is said that humans can identify and discriminate up to a trillion different odor mixtures. For chemoreception to have such a high discriminatory power, would require a diverse population of cells dedicated for odor detection. These detector cells are the olfactory sensory neurons (OSNs), which express odorant receptors (ORs) that bind to chemical odors in the environment. In order to increase specificity and sensitivity, an essential property in olfaction is for each OSN …

The Roles Of Inhibition In C. Elegans Locomotion, Lan Deng

Dissertations

Inhibition plays important roles in modulating neural activities at different levels from small synapses to brain regions, and different systems from sensory to motor. To achieve translocation, locomotor systems produce alternation of antagonist muscles, including axial posture and limb movement and alternation. In the nematode C. elegans, a cross-inhibition circuit, involving excitatory cholinergic and inhibitory GABAergic motoneurons, is believed to generate the dorsoventral alternation of body-wall muscles that supports backward undulatory locomotion. This dissertation challenges this prevalent hypothesis, delves into studying different roles of inhibition, and depicts the expression pattern and functional role of ionotropic GABAA receptor, UNC-49, in motoneurons …

Cytotoxic Analysis Of Old Drugs: New Drugs For Alzheimer’S Disease, Sebastian Yumiseba

Theses and Dissertations

Microglia are the resident immune cells of the CNS and constitute about 10% of all cells in the CNS. They have a vital role in Alzheimer’s pathogenesis as either cytotoxic or neuroprotective. Recent efforts are being put into repurposing drugs to target the microglia to treat Alzheimer’s disease.

The Role Of Apolipoprotein E In Alzheimer Disease: From Therapy To Mechanism, Tien-Phat Vuong Huynh

Arts & Sciences Electronic Theses and Dissertations

Alzheimer’s disease (AD) is a neurodegenerative disorder associated with irreversible damage to the brain, which manifests in cognitive dysfunction, memory loss, and eventual death. The pathological hallmarks of AD are amyloid plaques, which are cerebral aggregates consisting of fibrils of the amyloid β-protein (Aβ), and filamentous lesions of the microtubule-associated protein tau known as neurofibrillary tangles. In the early 1990s, the apolipoprotein E (apoE) was found to co-localize with amyloid plaques. The ε4 allele of the APOE gene was sequentially identified as the strongest genetic risk factor for AD, increasing the risk by 4 – 12-fold, whereas the ε2 allele …

Sexually Dimorphic Alterations In Brain Morphology Of Astrocyte Conditional System Xc- Knockout Mice, Gabrielle Emily Samulewicz

Honors Capstone Projects - All

Astrocytes play a vital role in orchestrating the precise brain wiring that occurs during development and are essential for maintaining homeostasis into adulthood. The cystine/glutamate antiporter, system xc-, in the central nervous system is especially abundant in astrocytes and itself is known to contribute importantly to the basal extracellular glutamate concentration as well as the intracellular and extracellular glutathione levels, either of which, if perturbed, could alter brain development and/or contribute to degeneration. Thus, to determine whether loss of astrocyte system xc- might alter brain morphology, I studied a conditional astrocyte system xc- knockout mouse (AcKO). Tissue was harvested from …

The Effects Of A New Mutation In Lis1 And Its Potential Role In Autism Spectrum Disorder, John A. Slovensky

Senior Theses

LIS1 is a protein, particularly concentrated in the brain, that is important in regulating the movement and transport capabilities of dynein. Dynein is protein that can move along pathways in the cell, carrying various cellular components and also helping brain cells migrate. These two proteins are crucial during the development of the nervous system, and mutations in them can lead to lissencephaly, a disorder in which the brain does not form properly. This disease causes patients to develop cognitive-motor defects and seizures that can lead to early death. While all previously identified mutations in LIS1 are known to cause lissencephaly, …

The Expression Of Mtor And Trib3 In Oligodendrocyte Lineage Cells, Katie Lazur

Senior Theses and Projects

Oligodendrocytes are a type of glial cell in the central nervous system that are responsible for producing the myelin sheath which allows for faster neuronal firing rates. Myelin production is a metabolically expensive process, which requires the oligodendrocytes to be aware of the nutrients are available to them. It has been demonstrated that the mammalian target of Rapamycin (mTOR) is required for the later stages of maturation in oligodendrocytes. However, when mTOR is inhibited by Rapamycin in the early stages of oligodendrocyte development, the oligodendrocytes are still able to fully differentiate. Tribbles Homolog 3 (Trib3) is a pseudo …

Amino Acid Sensing Ability By The Mechanistic Target Of Rapamycin In Oligodendrocytes, Emma England

Senior Theses and Projects

Oligodendrocytes (OLs) are a type of glial cell in the central nervous system that require substantial nutrients such as lipids and amino acids to create the extensive, metabolically expensive myelin sheath surrounding the axons of neurons. The mammalian target of rapamycin (mTOR) is a regulatory kinase that is necessary for the maturation of progenitor OLs through their distinct oligo-lineage phases. Amino acids are vital for the functioning of cells. The focus of this study was to determine if mTOR activity is dependent on the availability of leucine, methionine, and alanine. This was assessed by examining the phosphorylation level of the …

Mushroom Body-Specific Gene Regulation By The Swi/Snf Chromatin Remodeling Complex, Kevin Cj Nixon

Electronic Thesis and Dissertation Repository

Over the lifetime of an organism, neurons must establish, remodel, and maintain precise connections in order to form neural circuits that are required for proper nervous system functioning. Disruptions in these processes can lead to neurodevelopmental disorders such as intellectual disability (ID) and autism spectrum disorder. Mutations in genes encoding subunits of the SWI/SNF chromatin remodeling complex have been implicated in ID, yet the role of this complex in neurons is poorly understood. In this project, I established cell-type specific methods to examine the effect of SWI/SNF subunit knockdowns on gene transcription and chromatin structure in the memory-forming neurons of …

De-Coding The Impact Of Evolved Changes In Gene Expression And Cellular Phenotype On Primate Evolution, Trisha Zintel

Doctoral Dissertations

The goal of the dissertation work outlined here was to investigate the influence of proximal processes contributing to evolutionary differences in phenotypes among primate species. There are numerous previous comparative analyses of gene expression between primate brain regions. However, primate brain tissue samples are relatively rare, and my results have contributed to the pre-existing data on more well-studied primates (i.e. humans, chimpanzees, macaques, marmosets) as well as produced information on more rarely-studied primates (i.e. patas monkey, siamang, spider monkey). Additionally, the primary visual cortex has not previously been as extensively studied at the level of gene expression as other brain …

A Neural Mechanism For Capnotaxis In The Naked Mole-Rat, Michael Zions

Dissertations, Theses, and Capstone Projects

A Neural Mechanism for Capnotaxis in the Naked Mole-Rat

The Naked Mole-Rat (NM-R) is a small hairless rodent that has thrived underground in the Horn of Africa for the past 40 million years. It was first discovered in 1847, but has only been maintained in captivity and studied as a laboratory animal over the past 40 years. To date, more than 400 scientific papers have been published on this species. This is relatively few compared to established lab animals like rats and mice, but those papers contain a trove of information that has changed our understanding of the constraints of …

An Analysis And Representation In An Atlas Reference Space Of Putative Appositions From Neurons Expressing Alpha-Melanocyte-Stimulating Hormone With Neurons Expressing Hypocretin/Orexin Or Melanin-Concentrating Hormone, Vanessa Inez Navarro

Open Access Theses & Dissertations

The hypothalamus is a brain structure at the center of a variety of regulatory functions that have been explored by scientists and clinicians for almost a century. Among these functions, metabolic regulation and the control of appetitive behaviors have been fields of intensive research. Some of the major neural substrates involved in the hypothalamic control of feeding and the regulation of metabolic state include neuronal populations that express the neuropeptides alpha-melanocyte stimulating hormone (αMSH), melanin-concentrating hormone (MCH) and hypocretin/orexin (H/O). αMSH has been characterized in part as an anorexigenic peptide, while MCH and H/O have been characterized as having orexigenic …

Insights Into The Structure, Pharmacology, And Evolution Of The Glycine Transporter 2, Ashley Bryan Lopez

Open Access Theses & Dissertations

The balance between neuronal excitation and inhibition in the central nervous system is vital for survival. Overexcitation can be toxic and lead to certain manias or even death. On the other hand, extremely low levels of inhibition cause hyperekplexia, pain, and even forms of autism. Neuronal inhibition is, for the most part, achieved by two neurotransmitters, GABA and glycine. Levels of both neurotransmitters in the synaptic cleft are meticulously regulated by the GABA and glycine transporters, respectively, which belong to the solute carrier 6 (SLC6) family of neurotransmitter transporters and share structural similarities with other family members. In Chapter 1, …

Sex Differences In The Mechanisms That Modulate The Neurochemical Effects Of Nicotine, Kevin Uribe

Open Access Theses & Dissertations

Prior behavioral studies in our laboratory revealed that overexpression of the stress peptide, corticotrophin-releasing factor (CRF), in the mesocorticolimbic reward pathway enhanced the reinforcing effects of nicotine. The latter effect was greater in female versus male rats, suggesting that females are uniquely susceptible to the effects of stress on nicotine reinforcement. The goal of this dissertation was to examine the neurochemical mechanisms by which overexpression of CRF in the nucleus accumbens (NAc), a terminal region of the mesocorticolimbic pathway, modulates the behavioral effects of nicotine. Specifically, we examined whether nicotine-induced dopamine levels are altered by CRF overexpression via excitatory (glutamate) …

Distributions Of Axons Immunoreactive For Alpha-Melanocyte Stimulating Hormone And Neurons Immunoreactive For Neuronal Nitric Oxide Synthase In The Hypothalamus Of The Adult Male Rat: An Analysis Of Interactions And Their Representation In An Atlas Reference Space, Eduardo Peru

Open Access Theses & Dissertations

In the present study, we have provided two sets of high spatial-resolution maps for neuronal populations containing the immunoreactive presence of the key feeding-related peptides hypocretin/orexin (H/O), alpha-melanocyte stimulating hormone (αMSH) and the nitric oxide-producing enzyme, neuronal nitric oxide synthase (nNOS). These were mapped across the mediolateral and dorsoventral extents of the hypothalamus in the Swanson rat brain atlas, from levels 23–30. The first set of these maps are of the chemoarchitectural distributions for each of the neuronal populations mentioned, which are novel in two ways. First, they were generated across multiple animals to serve as the basis for probability …

Behavioral Ecology Of A Desert Ambush Predator: Assessing Movement Patterns, Habitat And Microhabitat Use, And The Innate Feeding Response Of Eastern Black-Tailed Rattlesnakes (Crotalus Ornatus) In The Northern Chihuahuan Desert, James Emerson

Open Access Theses & Dissertations

Research on the ecology and evolution of rattlesnakes has been sporadic over the past 80 years, but has seen recent expansion into the diverse fields of physiology, physiological ecology, life history, behavioral ecology, ethology, reproductive biology, chemical ecology, venom biochemistry and medicine, conservation, and many other subdisciplines. The development of small, implantable VHF radiotransmitters in the 1980s revolutionized research in the field of behavioral ecology for rattlesnakes, which are uniquely suited for radiotelemetry studies because they possess several morphological, physiological, and behavioral characteristics that are unique among terrestrial vertebrates. The widespread application of radiotelemetry by the mid-1980s advanced the model …

The Role Of Melatonin In Biological Rhythms Of Songbirds, Clifford E. Harpole

Theses and Dissertations--Biology

In vertebrates, melatonin is a hormone that is produced and secreted at night and inhibited by light. This unique “darkness-only” expression profile makes it an intellectually appealing candidate for a means of transmitting temporal information to an individual, both time of day and time of year.

In passerine birds, “time of day” information is certainly transmitted via melatonin secretion. The primary producer of systemic melatonin in this family of birds is the pineal gland, and surgical removal of it causes a bird to become arrhythmic in constant conditions. I find that as pinealectomized house sparrows (Passer domesticus) become …

Characterizing The Requirements For The Matricellular Protein, Dccn, In Nervous System Function, Elizabeth L. Catudio Garrett

Graduate Student Theses, Dissertations, & Professional Papers

The brain is organized as a complex network of specialized neurons that communicate via a combination of electrical and chemical signals. Our brains function to generate movement, control organ function, or direct complex behaviors; all of which requires the ability to regulate the flow of communication between circuits and networks. Work in this thesis addresses two areas of neuron communication: first, how does the release of more than one neurotransmitter from a single neuron impact behavior, and second, are matricellular proteins (MCPs) key contributors to synaptic transmission and neuron function? The conserved CCN family of MCPs have a …

Combination Of Investigational Cell-Based Therapy And Deep Brain Stimulation To Alter The Progression Of Parkinson’S Disease, Nader El Seblani

Theses and Dissertations--Pharmacy

Parkinson’s disease (PD) is the second most common neurodegenerative disorder and the motor symptoms are caused by progressive loss of midbrain dopamine neurons. There is no current treatment that can slow or reverse PD. Our current “DBS-Plus” clinical trial (NCT02369003) features the implantation in vivo of autologous Schwann cells (SCs) derived from a patient’s sural nerve into the substantia nigra pars compacta (SNpc) in combination with Deep Brain Stimulation (DBS) therapy for treating patients with advanced PD.

The central hypothesis of our research is that transdifferentiated SCs within conditioned nerve tissue will deliver pro-regenerative factors to enhance the survival of …

The Dysregulation Of Circadian Rhythms And Its Relation To Hippocampal Neurodegenerative Disease, John Patrick Mccauley

Legacy Theses & Dissertations (2009 - 2024)

Circadian rhythms modulate body temperature, sleep-wake cycles and cognitive functions like learning and memory. Interestingly, patients suffering from neurodegenerative disease like Alzheimer’s disease and brain insults like traumatic brain injury experience dysregulated circadian rhythms and learning and memory deficiencies as a symptom. The core molecular machinery that establishes these rhythms relies on the activation of positive and negative transcriptional-translational feedback loops within the hypothalamic suprachiasmatic nucleus (SCN). Subordinate circadian oscillators distributed throughout the peripheral and central nervous system follow the rhythmic activity of the SCN. One of these, the hippocampus, is mostly involved in regulating memory formation and recall. Experimental …

Role Of Smad4 Dependent Signaling In Controlling The Functioning And Connectivity Of Basal Vomeronasal Sensory Neurons, Ankana S. Naik

Legacy Theses & Dissertations (2009 - 2024)

ABSTRACT

Effect Of Draxin Manipulation On Btbr Mouse Brain And Behavior, Adam Blau

Legacy Theses & Dissertations (2009 - 2024)

Autism Spectrum Disorder (ASD) is known for distinct behavioral phenotypes such as a preference for repetitive activities and difficulty in socialization. However, little is known about what might cause ASD. Current evidence implicates genetics as playing a substantial role in ASD. Mouse models, such as BTBR T+ Itpr3tf/J (BTBR) inbred mice, are an invaluable resource for ASD research, as they allow the investigation of both genetics and behavior in parallel. BTBR mice are of interest due to their reduced hippocampal commissure (HC) and absent corpus callosum (CC), along with increased exploratory activity, decreased anxiety, reduced sociability, and increased repetitive self-grooming …

Neurodegenerative Modeling: Tau Protein, Degradative Pathways, And Gene Expression Profiling Of Human Ipsc-Derived Neural Precursors And Differentiated 3-D Neural Sphere Versus 2-D Monolayer Cultures, Kyle H. Anthoney

Cal Poly Humboldt theses and projects

Human induced pluripotent stem cells offer a model for human brain development and disease by differentiation into brain organoids; however, current neural culture systems lack the microenvironment, neuronal circuits and connectivity, vascular circulation, and immune system that exist in vivo. After differentiation and development of neuronal and non-neuronal cell types within two formats of cell cultures, we can visualize and recapitulate in vivo protein accumulation, gene expression, and degradative processes such as autophagy. Using RNA extraction, purification methods and reverse transcription I compared traditional monolayer cultures and novel 3-D neural sphere cultures via gene expression analysis. This analysis indicated …

Neuroanatomy Of The Blackspotted Rockskipper, Entomacrodus Striatus, Pooja Dayal

Williams Honors College, Honors Research Projects

Here I characterized the central neuroanatomy of the Blackspotted Rockskipper, Entomacrodus striatus, native to French Polynesia. The neuroanatomy of E. striatus has not been studied prior to this paper. I used several histology and antibody staining techniques to accomplish this, including Crystal Violet, immunohistochemistry, immunofluorescence, and Bielschowsky’s Silver Nitrate staining. This paper describes the most successful techniques used, identifies major structures in the species’ neuroanatomy, and also explains why studying E. striatus is important in the future of vertebrate research.

Assessing Morphology Of Iprgcs After Traumatic Brain Injury, Brian Foresi, Matt Smith

Williams Honors College, Honors Research Projects

ipRGCs are retinal ganglion cells that project to visual processing centers of the brain for nonimage forming visual functions. The relation of ipRGCs to tramatic brain injury (TBI) is emerging as data has been published describing ipRGC functional changes in TBI affected military veterans. Major symptomologies of concussions, a mild form of TBI, also overlap with the function governed by sites in the brain with major ipRGC projection percentages. Assesing if a morphological change is occuring in the ipRGCs after a TBI could support the idea of a pathological mechanism of the injury. This study could also indicate further relevance …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Reprograming Neuronal Cells By Overexpression Of Fibroblast-Specific Transcription Factors, Abdulmohsen Alanazi

Masters Theses

In mammals, a complex system of regulatory signals distinguishes tissues, structures and functions. Combinations of transcription factors and co-factors regulate activation and repression of genes that result in cellular differentiation. Whole genome arrays allow the monitoring of genomic expression in specific tissues. Fibroblast microarray studies have shown candidate genes that may be involved in fibroblast identification, including genes that express transcription factors Prrx1, Snai2 and Twist1. A previous study showed that the Prrx1 and Snai2 could reactivate a fibroblast phenotype in hybrid cells that had lost fibroblast identity. Furthermore, overexpression of these factors in liver-derived cells strongly repressed liver gene …