Life Sciences Commons^™

Metrics For Comparison Of Complex Networks, Clarissa Reyes

Open Access Theses & Dissertations

Heuristic network statistics are used as a preliminary approach to identify change across networks. In networks where there is known node correspondence (KNC), conventional network comparison methods include taking a norm of the difference matrix, or calculating dissimilarity measures like DeltaCon and cut distance. Since different KNC measures provide varying insight to the network comparison problem, we propose employing Rank Score Characteristic Functions (RSCFs) and the rank-score process as a method for reaching a consensus when ranking quantified change across multiple pairs of networks â?? which is particularly useful for ranking change across subpopulations or subgraphs. Additionally, we propose a …

Characterization Of Potential Genes Encoding For A Glycine Transporter From Drosophila Melanogaster, Denise Avalos

Open Access Theses & Dissertations

The study of glycine transporters has been neglected compared to other members of the Solute Carrier 6 (SLC6) family of proteins, such as the dopamine and serotonin transporters, even though they are just as crucial to survival. However, glycinergic neurotransmission has been extensively studied in mammals, resulting in vast, valuable information. The same cannot be said for invertebrates, however. In this study, we aim to establish an initial first step in elucidating components of glycinergic neurotransmission in the invertebrate, Drosophila melanogaster. We believe this organism possesses a glycine transporter because a glycine receptor has been identified and characterized. Specifically, we …

A Novel Neuroinvasive Infection Modality For Francisella Tularensis Elicits Neuroinflammation Resulting In Cellular Damage, Mireya Griselle Ramos-Muniz

Open Access Theses & Dissertations

Francisella tularensis (Ft.) is a gram-negative coccobacillus bacterium that causes the zoonotic disease tularemia in humans. Ft. causes the most severe, often fatal, form of the disease through inhalation. However, Ft. is most commonly transmitted through direct contact with infected animal carcasses such as rodents and rabbits, consumption of contaminated food or water, or through arthropod bites, particularly ticks. Due to its extremely low infectious dose, high mortality rate, and potential use as a biological warfare agent, Ft. is classified by the CDC as a "Tier 1 select agent". Ft. infection triggers an overactive inflammatory response, termed a "cytokine storm", …

Connectional Analysis Of Brain Regions Associated With Feeding, Kenichiro Negishi

Open Access Theses & Dissertations

Rodent models are invaluable for understanding the foundations of motivatedbehaviors. One major obstacle faced by these efforts is the lack of a 'wiring diagram' or a 'parts list' of structures that support motivated behaviors. Here, I present work that advances our knowledge of the structural organization of connections and chemoarchitecture of the diencephalon. Chapter 1 aims to clarify a wiring diagram of the medial prefrontal cortex (mPFC) following a recent demonstration of cortically-evoked feeding through this region. Chapter 2 clarifies the distributions of a subpopulation of tyrosine hydroxylase (TH) neurons in the hypothalamus. These disparate datasets were analyzed and interpreted …

Neurogenetic Function Of Host Cell Factor-1, Victoria Lynn Castro

Open Access Theses & Dissertations

Neural precursor cells (NPCs) are the stem-like cells of the developing brain. These cells differentiate into the differentiated cell types of the central nervous system. If disruption occurs in the number of total NPCs formed or their survival, various disorders including learning disabilities, behavioral problems, or epilepsy can occur. This dissertation describes how the HCFC1 gene controls the proliferation and differentiation of NPCs. HCFC1 encodes for a transcriptional co-factor that regulates the growth and metabolism of stem cells, including NPCs. Mutations in HCFC1 cause cblX syndrome, a neural developmental disorder that affects the nervous system and causes microcephaly, epilepsy, and …

Region Detection & Segmentation Of Nissl-Stained Rat Brain Tissue, Alexandro Arnal

Open Access Theses & Dissertations

People who analyze images of biological tissue rely on the segmentation of structures as a preliminary step. In particular, laboratories studying the rat brain delineate brain regions to position scientific findings on a brain atlas to propose hypotheses about the rat brain and, ultimately, the human brain. Our work intersects with the preliminary step of delineating regions in images of brain tissue via computational methods.

We investigate pixel-wise classification or segmentation of brain regions using ten histological images of brain tissue sections stained for Nissl substance. We present a deep learning approach that uses the fully convolutional neural network, U-Net, …

Morphine-Induced Tolerance Is Reduced By The Consumption Of A Ketogenic Diet, But Not A High Fat/High Carbohydrate Diet, Nina Beltran

Open Access Theses & Dissertations

Opioid drugs like morphine are used medicinally for pain relief, but also have abuse liability that can lead to opioid use disorder (OUD), which contributes to nearly 70% of drug overdose deaths in the United States. Another rising health concern is the global obesity epidemic, and new evidence suggests that obesity and OUD might converge to impact individuals. For example, high body mass index (BMI) is associated with greater reports of pain among women. Further, opioid overdose risk is increased among individuals diagnosed with obesity, suggesting a potential relationship that might convey enhanced vulnerability among some populations. Given the high …

Sex And Age Differences In Approach Behavior Toward A Port That Delivers Nicotine Vapor, Veronika Evangelina Espinoza

Open Access Theses & Dissertations

The goal of our laboratory is to study the mechanisms that promote nicotine use, particularly in vulnerable populations such as adolescents and females. Thus, the purpose of this thesis was to characterize age and sex differences in the motivational/rewarding effects of nicotine (Aim 1) and withdrawal behavior (Aim 2). To more closely model human use patterns, the present study employed nicotine vapor methods involving passive exposure for 14 days in adolescent and adult female and male rats. Age and sex differences in approach behavior (nosepokes) were assessed in a port that delivered nicotine plumes on Day 1 and 14. Controls …

Transgenerational Differences Between Two Culturally Distinct Prairie Vole Populations, Richard Joaquin Ortiz

Open Access Theses & Dissertations

Culture can be described as a system of environmental beliefs, values, and social practices within one’s environment. This system is passed on from generation to generation and provides a basis for an individual’s behaviors and cognitive perceptions. Cultural neuroscience is an emerging field that intertwines domains of anthropology, psychology, neuroscience, and genetics to help understand the underlying processes, neural mechanisms and genomic factors that vary across cultures. Similar to humans, the socially monogamous prairie vole (Microtus ochrogaster) display populational differences in prosocial behavior and aggression based upon region-specific cultural upbringing and parental lineage. Prairie voles originating from Kansas (KS) display …

Long-Term Effects Of Adolescent Fluoxetine Exposure On Hippocampal Gene Expression In Male C57bl/6 Mice, Anapaula Themann

Open Access Theses & Dissertations

Mood-related disorders, including depression and anxiety, are prevalent among children and adolescents. This poses a public health challenge, given their adverse impact on these young populations. Treatment with the selective serotonin reuptake inhibitor fluoxetine (FLX) is the first line of pharmacological intervention in pediatric patients suffering from affect-related illnesses. Although the use of this antidepressant has been deemed efficacious in the juvenile population, the enduring neurobiological consequences of adolescent FLX exposure are not well understood. For this reason, we explored for persistent molecular adaptations, in the adult hippocampus, as a function of adolescent FLX pretreatment. To do this, we administered …

Impact Of Xenobiotics On Neuronal Outcomes, Gabriela Henriquez

Open Access Theses & Dissertations

Neurodegenerative diseases are a common affliction of the Central Nervous System. They are caused by age, genetics, and environmental factors. Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic Lateral Sclerosis are well-known among the host of neurodegenerative disorders, with Alzheimer's disease and Parkinson's disease being the leading pathologies across this canvas. It is known that the pathogenesis of neurodegenerative diseases is multifactorial due to the involvement of genetic mutations, radical-induced protein damage, abnormal aggregation of misfolded proteins, and the formation of amyloid deposits. The amyloid proteins in neurodegenerative disease include Tau and Amyloid (Aβ) in Alzheimer's disease and α-Synuclein in …

A Proposed Mechanism For Stimulant-Induced Behavioral Sensitization Involving The Transporter Vmat, Valeria Garcia

Open Access Theses & Dissertations

Elucidating mechanisms that drive drug craving is crucial to develop pharmacological interventions for addiction. Repeated exposure to psychostimulants produces an enhanced behavioral and neurochemical sensitivity to both the drug and drug-related cues, known as sensitization. We hypothesize that VMAT, the protein responsible for storage of dopamine (DA) into the vesicles, may be functionally altered to redistribute DA between the cytoplasmic pool and the vesicular pool based on demands for drug-mediated release versus neurotransmission in the context of conditioned environmental cues. To examine the role of VMAT, we pretreated rats with a VMAT blocker, tetrabenazine (TBZ), before each daily treatment of …

Chanism Of G-Βγ-Dependent Regulation Of Neuronal Differentiation And Neurodegeneration, Diana Olivas

Open Access Theses & Dissertations

Neurodegeneration is a pathological condition associated with a progressive loss of neurons, and occurs in many neurological disorders including Alzheimer’s disease (AD), Parkinson’s disease (PD) and Lou Gehrig’s disease (ALS). It is the most common cause of dementia among people 65 and older. With the increasing of life expectancy, the prevalence of neurodegenerative diseases is also increasing rapidly. However, the cause of this disorder is largely unknown, and no effective drugs are available to treat the disease process. Therefore, it is crucial to identify new target(s) and strategies for therapeutic interventions. Cytoskeletal defects followed by dysfunction is a major characteristic …

Effects Of Repeated Nicotine Vapor Exposure And Withdrawal On Somatic Signs, Anxiety-Like Behavior, And Brain Reward Thresholds In Male Sprague Dawley Rats, Michelle Martinez

Open Access Theses & Dissertations

No abstract provided.

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, …

Insulin Restores The Neurochemical Effects Of Nicotine In The Mesolimbic Pathway Of Diabetic Rats, Bryan Cruz

Open Access Theses & Dissertations

This study examined whether insulin modulates the neurochemical effects of nicotine in the mesolimbic pathway of diabetic rats. Rats received vehicle or streptozotocin (STZ) to induce hypoinsulinemia. A subset of STZ-treated rats was implanted with insulin pellets that rapidly normalized glucose levels. Two-weeks later, dialysis probes were implanted into the nucleus accumbens (NAc) and ipsilateral ventral tegmental area (VTA). The next day, dialysate samples were collected during baseline and then following systemic administration of nicotine. Samples were also collected following intra-VTA administration of the gamma-aminobutyric acid (GABA)A receptor antagonist, bicuculline. Dopamine, acetylcholine (ACh), GABA, and glutamate levels were assessed using …

Juvenile Fluoxetine Treatment Mediates An Anxiogenic Phenotype That Is Ameliorated By Its Re-Exposure In Adulthood, Francisco Javier Flores Ramirez

Open Access Theses & Dissertations

Accumulating preclinical evidence indicates that early-life exposure to psychotropic medications induce an anxiogenic-like behavioral profile in later life. However, these preclinical approaches have been conducted primarily using male subjects. This is problematic since clinical data indicates that women are more likely to be diagnosed with anxiety disorders than their male counterparts, and thus, women are prescribed with psychotropic medications like fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI), at significantly higher rates. Therefore, the goal of this Dissertation is to examine whether alterations in behavioral responses to anxiety-eliciting stimuli are exhibited in adulthood, as a result of early-life FLX exposure. …

Toward Automated Region Detection & Parcellation Of Rat Brain Tissue Images, Alexandro Arnal

Open Access Theses & Dissertations

People who analyze images of biological tissue often rely on segmentation of structures as a preliminary step. In particular, laboratories studying the rat brain manually delineate brain regions to position scientific findings on a brain atlas to propose hypotheses about the rat brain, and ultimately, the human brain. Our work intersects with the preliminary step of delineating regions in images of brain tissue via computational methods.

We investigate pixel-wise classification or segmentation of brain regions using ten histological images of brain tissue sections stained for Nissl substance, and two deep learning models: U-Net and Tile2Vec. Our goal is to assess …

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 …

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) …

Ketamine Pre-Exposure Does Not Influence Later-Life Responses To Reward-Related Stimuli In Female C57bl/6 Mice, Israel Garcia

Open Access Theses & Dissertations

Preclinical work indicates that exposure to traditional antidepressant medications, in adolescent and adult female subjects, alters reward-related behavior later in life. In recent years, the anesthetic ketamine (KET), now used as a fast-acting antidepressant, has shown promising therapeutic efficacy for the management of depression. However, the potential long-term behavioral consequences of KET exposure across development have not been thoroughly assessed. Thus, to address this issue, we examined if KET exposure, during adolescence or early adulthood, results in enduring alterations in responsivity to the rewarding properties of sucrose and cocaine later in life. Specifically, female C57BL/6 mice were randomly assigned to …

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 …

Inhibition Of Glycine Transporter 2: An Emerging Target For Chronic Pain, Elvia Lilia Padilla

Open Access Theses & Dissertations

Chronic pain is a complicated, completely unknown condition that has been studied based on its severe impact on the population. According to the American Academy of Pain Medicine, 1.5 billion people suffer from tension-type headaches, one of the most common symptomatic chronic conditions. Christopher L. Cioffi, 2019; mentioned approximately in US 116 million adults are explicitly afflicted by chronic pain. Chronic pain is described as dysfunction in nerves that have been continuous during a long period (Mills, 2019). Treatments for chronic pain are different types of common analgesics that relieve the pain for short periods such as aspirin, ibuprofen, paracetamol, …

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 …

U.S. Perceptions Of Economic Mobility Since The Enactment Of Nafta And Their Impact On American Politics And Society, Jairemy Quinton Edwards

Open Access Theses & Dissertations

In this study, I examine how perceptions of NAFTA developed over 20 years since its enactment, measured as perceived economic mobility in 2016, have affected more recent public perceptions leading to increased, controversial tendencies towards nationalism, protectionism, and pessimism about the future of the U.S. economy. I then assess whether and how such perceptions in turn may have affected voter perceptions about Donald Trump, setting the stage for his 2016 election victory. Therein, I have found that among U.S. voters in 2016, those with perceptions of reduced economic mobility since the enactment of NAFTA were significantly more likely to have …

Shining Light On An Amygdala -- Brainstem Connection Important For Attention Processing, Jose Carlos Cano

Open Access Theses & Dissertations

We are continuously being exposed to an exorbitant amount of sensory information, which should result overwhelming. However, the nervous system operates several intrinsic sensory filtering mechanisms that allow us to cope with such sensory cluttering and shape appropriate behavior. Sensorimotor gating is a pre-attentive neuronal filtering mechanism that gates superfluous sensory information, and orients attentional resources towards salient information processing. Its relevance becomes in individuals suffering from schizophrenia and several otherwise unrelated neuropsychiatric disorders where sensorimotor gating is impaired. To understand the neural impaired mechanisms, extensive research studies have focused on first identifying the neural substrates underlying sensorimotor gating. This …

Identification Of The Cell Type Expressing The Glycine Transporter 1 (Glyt1) In The Thalamus, Patricia A. Lozano

Open Access Theses & Dissertations

Glycine acts as an inhibitory neurotransmitter and a co-agonist of NMDAR at the glutamatergic synapses. Termination of glycinergic neurotransmission is achieved by glycine transporter 1 (GlyT1) and glycine transporter (GlyT2). Both transporters are expressed in the spinal cord, brainstem and cerebellum, but GlyT1 is also expressed in the retina and the forebrain. Previous studies have described the role and cyto- architecture of GlyT1 in the caudal areas of the brain and retina, but not in the structures of the forebrain. Based on our preliminary data, GlyT1 is highly expressed in the thalamus, an area involved in sensory and motor signal …

The Effectiveness Of The Natural Ear On Adults Ability To Accurately Match Pitch, Kendra Nicole Rosales

Open Access Theses & Dissertations

Background: Many theories, such as oral motor, perceptual, and sensorimotor deficits, have been posited to explain inaccurate pitch matching abilities. The current study identifies with the sensorimotor deficit theory and found it to be the most plausible explanation for inaccurate singing abilities. The Natural Ear (NE) program was designed to process voice productions in real-time and filter out the discordant harmonics, allowing a person to hear only their F0.

Purpose: The purpose of this study was to examine the effectiveness of the Natural Ear program in increasing pitch matching accuracy in singers.

Methods: A total of 50 participants were included …

Molecular Mechanism Of Neurodegeneration Induced By 4-Nonylphenol, Michelle Alejandra Aranda

Open Access Theses & Dissertations

Neurodegeneration, a progressive loss of nerve cells, occurs in many neurological disorders, including Alzheimer's disease (AD) and Parkinson's diseases (PD), as well as in dementia. The pathogenesis of these diseases is unknown, and recent evidence suggests that environmental factors, which act as endocrine-disrupting compounds (EDCs) could play a significant role in developing the disease process. 4-Nonylphenol (4-NP), an EDC, and a ubiquitous environmental toxin has been shown to affect brain development and may cause neurodegeneration. 4-NP is produced in large quantities in the U.S. and used as raw materials for making detergents, pesticides, plastics, paints, cosmetics, rubber, and other industrial/household …

The Language Content Of Computer-Mediated Versus Face-To-Face Motivational-Type Interviews, Karla Deyanira Llanes

Open Access Theses & Dissertations

Motivational Interviewing (MI) is an extensively used technique to facilitate behavior change by increasing a person's own motivation and commitment toward change. Recently, several innovative and effective ways to conduct motivational interviews have emerged. However, one potential option has not been investigated: the utility of conducting a motivational interview via computer. The current study begins to address this gap in knowledge by comparing the language content of computer-mediated motivational-type interviews and face-to-face motivational-type interviews. The motivational-type interviews were conducted with young adults who reported ambivalence about their level of recreational marijuana use. Specifically, non-marijuana users, occasional marijuana users, and frequent …