Neuroscience and Neurobiology Commons^™

Cross-Cue Reactivity Of Nicotine And Cannabis Vaping Products, Madeline Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

SIGNIFICANCE. The rewarding properties of nicotine increase when administration is paired with external stimuli, or “cues”, including those related to vaping products. Given the visual similarity between nicotine vaping products (NVPs) and THC vaping products (TVPs), exposure to one product may elicit reactivity (e.g., craving, urge to use) to the other. The present study aimed to develop a set of cues capable of differentiating NVPs from TVPs to inform investigations of cross-cue reactivity. METHODS. Images (n=61 NVPs; n=64 TVPs; 7=unspecified) were obtained via an online search using both generic (“vape”, “vape pen”) and product-specific (e.g., “nicotine vape”, “dab pen”) keywords …

Effects Of Pubertal Stress On Later Pup-Directed Behavior In Pregnant And Non-Pregnant Adult Female Mice, Marissa Marylin Nicodemus

Graduate Theses, Dissertations, and Problem Reports (ETD)

Beginning in adolescence and throughout adulthood, women are at an increased risk for anxiety and mood disorders compared to men. Several risk factors for these disorders have been identified, but it is not clear how they interact. One such factor is pregnancy. The normative changes to the brain and behavior that occur during and after pregnancy are associated with an increased risk for anxiety and mood disorders. Exposure to adverse childhood experiences (ACEs) has also been associated with an increased risk of mood disorders, and compared to men, women appear to be particularly vulnerable to the lasting effects of stress …

Neural And Computational Approach To Understanding Environmental Modulation Of Behavioral Identity In Zebrafish, John W. Hageter

Graduate Theses, Dissertations, and Problem Reports (ETD)

Organisms rely on behavior for survival. Animals engage in behaviors that allow for feeding, mating, exploring and navigating their environment among others. Necessary for these behaviors to develop are the environmental factors and underlying circuitry which make behavior possible. Specifically, how the environment guides underlying neural circuitry to develop unique facets or phenotypes of a larger behavior are key to understanding why unique behaviors exist. In this thesis, I build foundational evidence for determining these mechanisms through the use of the zebrafish local search behavior. This is a behavior that zebrafish employ following the loss of environmental illumination where they …

Neurobiological Variables Mediating The Relationship Between Breast Cancer And Sleep Disruption, Brittany Domenique Elliott

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neurobiological Variables Mediating the Relationship between

Breast Cancer and Sleep Disruption

Brittany D. Elliott, MS

Breast cancer is the most commonly diagnosed malignancy in women, with more than two million new cases diagnosed world-wide each year. Improvements in screening technology and diagnostics have increased survival rates, but cancer-associated sleep disruptions persist for the majority of breast cancer survivors well beyond the treatment period. In addition to reducing quality of life, reduced sleep quality is associated with greater incidences of affective dysfunction, reduced treatment efficiency, aggressive cancer progression, increased symptom severity, and increased mortality by all causes. Thus, identifying the variables …

Co-Transmission Is Co-Opted For The Coordination Of Auditory Sensory Integration, Marryn M. Bennett

Graduate Theses, Dissertations, and Problem Reports (ETD)

Corollary discharge circuits (CDCs) are conserved mechanisms for sensory modulation during species specific behavioral programs. Many behaviors require multiplexed differential sensory modulation for proper execution. Co-transmission of fast and slow neurotransmitters allows for distinct modulation of different downstream targets within one sensorimotor circuit. However, studying co-transmission within the context of modulatory circuits like CDCs requires complete knowledge of behavioral circuits and precise tools for individually determining the implications of each transmitter on its targets. In this dissertation, I used a conserved set of corollary discharge interneurons in Drosophila melanogaster as a model to study the intricacies of sensory modulation through …

The Effect Of Cerebellar Feedback On The Spatial Processing Of Conspecific Signals In The Electrosensory System, Dakota Ray Miller

Graduate Theses, Dissertations, and Problem Reports (ETD)

Animals have evolved sensory systems to help decipher important environmental signals that are vital for their survival. Feedback pathways are necessary to allow these signals to stand out in a noisy background, enabling the animal to focus on them more effectively. The electrosensory system of Apteronotus leptorhynchus allows the fish to sense the modulations caused by other conspecifics to allow for proper responses during social interactions. Electroreceptors detect these EODs, and afferent nerves project these signals to the ELL, where electrosensory information is projected to other parts of the brain. Cerebellar feedback to the ELL allows the suppression of lower …

Individual And Collective Properties Of Tunable Photochemical Belousov-Zhabotinsky Micro-Reactors, Kudakwashe Benedict Shumba

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cell-like model chemical systems are powerful tools that can be used to explore the role of intercellular coupling on population level behaviors in communities of biological cells. Firstly, we present a new method for fabricating such micro-reactors using the photosensitive Belousov–Zhabotinsky (BZ) reaction system employed in silica microparticles. These BZ micro-reactors have a tunable response to photochemical coupling, varying from a fully excitatory response to a fully inhibitory response. Their response can be tuned through variations in either the reactive mixture or, on an individual micro-reactor level, by changes in the synthesis temperature used during the fabrication of the silica …

Ciliary Arl14b In Vision, Alexis Breann Crockett

Graduate Theses, Dissertations, and Problem Reports (ETD)

Primary cilia are highly specialized organelles that regulate signaling, trafficking, and sensory perception across multiple tissues, including the retina. The small GTPase ADP Ribosylation Factor-Like Protein 13B (ARL13B) is an atypical ARF-family protein enriched in cilia. ARL13B acts as a guanine exchange factor (GEF) for another small GTPase ARF-like Protein 3 (ARL3). Mutations in ARL13B cause Joubert syndrome, a ciliopathy characterized by brain malformation, developmental delays, and retinal degeneration. Despite ARL13B’s known ciliary localization and clinical relevance, ARL13B’s precise functions in cilia remain poorly defined. This dissertation investigates the cilia-specific roles and GEF-specific roles of ARL13B in photoreceptors using two …

Sleep, Endocannabinoid Signaling, And Cortical Processing In Mouse Models Of Autism Spectrum Disorder, Bryan Rodriguez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sleep plays a crucial role in memory consolidation, neuronal plasticity, and cognitive function. Individuals with autism spectrum disorder (ASD) often experience sleep disturbances, which are positively correlated with symptom severity. However, on the surface, sleep architecture is remarkably normal under baseline conditions in many rodent models of ASD. The goals if this dissertation were to investigate whether regulation of sleep, biochemical signaling during sleep, and downstream consequences of sleep on behavior are altered in two mouse models of ASD. In Aim 1, we tested the hypothesis that sleep phenotypes emerge in ASD models under conditions of high sleep pressure. We …

Characterization Of A Descending Neuron That Modulates Flight Performance And Provides Input Onto A Flight-Related Predictive Motor Circuit, Andisheh Balouchi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Descending neurons (DNs) play a critical role in sensorimotor integration by relaying motor information to the ventral nerve cord (VNC). Within the VNC, local interneurons, other DNs, and ascending neurons (ANs) make circuits with sensory and motor neurons to modify flies’ behavior. One important AN pair in Drosophila Melanogaster is mesothoracic ascending histaminergic neurons (MsAHNs), which are known to convey predictive wing motor signals to the brain. DNg32 is the primary upstream synaptic partner of MsAHNs, integrating DNg32 input with other inputs to generate predictive motor signals. The goals of this study were to 1) map the synaptic connectivity of …

Computational Approaches For Diagnosing Neurological Impairments And Restoring Functional Movement, Serhii Bahdasariants

Graduate Theses, Dissertations, and Problem Reports (ETD)

Movement is the primary means by which the nervous system converts intention into interaction with the environment. Voluntary limb motion enables standing, walking, reaching, and grasping—actions that underpin self‑care, communication, and economic participation. When diseases or injuries disrupt the pathways that couple neural commands to muscle forces—whether through cortical stroke, spinal cord injury, or peripheral nerve damage—mechanical outcomes such as weakness, loss of coordination, and ultimately reduced mobility emerge. These impairments cascade into secondary complications, increased dependence on caregivers, and diminished quality of life. Quantifying how the lesion alters the mechanics of movement is therefore essential for designing targeted interventions …

A Framework For Biomimetic Robot Design Applied To The Development Of A Robotic Model Of Drosophila Melanogaster, Clarissa A. Goldsmith

Graduate Theses, Dissertations, and Problem Reports (ETD)

For decades, the field of biologically inspired robotics has leveraged insights from animal locomotion to improve the walking ability of legged robots. Recently, “biomimetic” robots have been developed to model how specific animals walk. By prioritizing biological accuracy to the target organism rather than the application of general principles from biology, these robots can be used to develop detailed biological hypotheses for animal experiments, ultimately improving our understanding of the biological control of legs while improving technical solutions. Much of this work involves biologically inspired walking controllers informed by the morphology and dynamics of the insect nervous system, which necessitate …

Neuroendocrine Regulation Of The Luteinizing Hormone Surge And Puberty Onset In Sheep, Max J. Griesgraber

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and follicle stimulating hormone (FSH) are essential for the reproduction of all mammalian species, including both sheep and humans. GnRH is secreted by hypothalamic neurons into the hypophyseal portal vasculature in a pulsatile manner, which then acts within the anterior pituitary to elicit the release of LH and FSH into wider systemic circulation. In females LH and FSH act on the ovaries to promote estradiol (E2) production, follicular development, and under certain conditions in regard to LH, ovulation. Furthermore, while E2 inhibits GnRH and subsequent LH secretion under most conditions, at high concentrations E2 …

Simulated Slot Machine Gambling In Relation To Sign-Tracking, Polina Krom

Graduate Theses, Dissertations, and Problem Reports (ETD)

The propensity to attribute incentive salience to reward-related cues, or sign-tracking (ST) has been linked to addiction in animal models and some initial human data. The current study explores the role of sign-tracking (ST), as a potential risk factor for problematic slot machine gambling, which abundantly features audiovisual reward-related cues, henceforth sensory features. A sample of healthy participants without gambling problems (n = 30) completed a Pavlovian-to-Instrumental Transfer (PIT) paradigm to assess ST propensity and played on a realistic slot machine simulator consisting of two versions: with sensory features (SF+) and without (SF-). Each game version had fixed bet sizes, …

Measuring Activity Demands On Fatigue In Individuals With Parkinson's Disease, Laura R. Mccray, Kara M. Lee

Graduate Student Scholarship

The functional presentation of those with Parkinson's disease (PD) are complex, varying depending on cognition, physiological deficits, and support network. This study assesses the perceptions of fatigue across individuals with Parkinson's disease with different clinical presentations to guide clinicians in their selection of evidence-based interventions to facilitate greater functional outcomes. A mixed-methods design was used to collect data on the mental and physiological perceptions of fatigue, utilizing surveys and physiological measures such as heart rate. Participants were recruited from a community group targeting those with PD with inclusion criteria being a diagnosis of PD. Results for both heart rate and …

The Effects Of Diet-Induced Obesity On Cerebral Microvascular Bioenergetics, Alec Anthony Hanshew

Graduate Theses, Dissertations, and Problem Reports (ETD)

Obesity is a worldwide epidemic but is especially a concern in the United States with over 40% of the population being obese. Obesity is known to cause increased metabolic demand, systemic inflammation, peripheral vascular dysfunction, and increased levels of oxidative stress and reactive oxygen species (ROS). However, the role of obesity on cerebrovascular bioenergetic function has not been fully elucidated. This study aimed to determine the impact of diet-induced obesity on cerebrovascular bioenergetics. 72, 6-month-old C57Bl/6 male and female mice were randomized into control and HFD groups. Control mice were subjected to the feeding of standard chow (18% fat, 24% …

Investigating The Role Of Spinal Motoneuron Organization In Human Motor Control, Rachel I. Taitano

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mechanisms of voluntary motor control are complex and require inputs via cortical centers, peripheral sensory systems, and spinal inputs such as central pattern generators. It is hypothesized that control is simplified via utilization of motor primitives, which may rely on structures within the spinal cord, however this remains unknown in both human and non-human primates. The goal of this dissertation is to characterize muscle activity in the upper extremity in relation to the corresponding anatomical organization of spinal motoneurons to provide insight into how primitives are both organized and activated to produce movement.

The first aim of this work was …

Aberrant Lipid Accumulation And Retinal Pigment Epithelium Dysfunction In Prcd-Deficient Mice, Sree Indrani Motipally

Graduate Theses, Dissertations, and Problem Reports (ETD)

Progressive Rod-Cone Degeneration (PRCD) is a peripheral membrane protein predominantly expressed in photoreceptor outer segment (OS) disc membranes with an unknown function. Several mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans. The most common “cysteine to tyrosine” (C2Y) mutation in Prcd leads to progressive retinal atrophy in multiple dog breeds and RP in humans. Canine models harboring the C2Y mutation in Prcd show disorganized OS structure with greatly attenuated photoreceptor OS renewal rates. Recent studies show defects in the photoreceptor nascent disc flattening in the absence of Prcd. However, it is unclear how OS discs eventually …

Cerebellar Feedback Effects On Responses To Conspecific Signals Of Different Frequencies In The Electrosensory System, Elora K. Shinn

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensory systems in animals have evolved to translate physical stimuli into neural representations that, in turn, guide behavior. Feedback is critical in these processes, allowing organisms to filter redundant information and respond effectively to relevant stimuli. In humans, for example, the cerebellar flocculus provides feedback to the vestibulo-ocular reflex to stabilize eye movements during body rotation. In bats, the feedback during echolocation helps prioritize essential signals from the environment. In weakly electric fish, cerebellar feedback helps filter out redundant low-frequency modulations caused by conspecifics, enabling them to detect prey and other relevant signals. However, the influence of cerebellar feedback on …

Synaptic Zinc Transporters Support Normal Synapse Structure And Function In Mouse Auditory Cortex, Abbey Manning

Graduate Theses, Dissertations, and Problem Reports (ETD)

Many regions of the brain are highly enriched with free zinc inside glutamatergic vesicles at presynaptic terminals. At these synapses, zinc transporter 3 (ZnT3) moves zinc into vesicles where it is co-released with glutamate. Alterations in ZnT3 are implicated in multiple neurodevelopmental disorders, and ZnT3 knock-out (KO) mice – which lack synaptic zinc – show behavioral deficits associated with autism spectrum disorder and schizophrenia. Shank3 is a synaptic scaffolding protein that assists in tethering and organizing structural proteins and glutamatergic receptors in the postsynaptic density of excitatory synapses. The localization of Shank3 at excitatory synapses and the formation of stable …

Traumatic Brain Injury Induces Cerebrovascular Dysfunction: Consequences For Ischemia And Cerebral Hypoperfusion, Bailey J. Whitehead

Graduate Theses, Dissertations, and Problem Reports (ETD)

Traumatic brain injury (TBI) is a significant health concern across the United States as well as the broader globe, affecting millions of individuals on an annual basis. While most recover from their TBI and resume their lives normally, some subsets of TBI survivors continue to experience impairments and increased risk for future diseases like cardiovascular disease, stroke, and aging related disease like Alzheimer’s Disease or VCID.

TBI remains a fundamentally difficult neurological injury to pin down mechanistically, due to the variability in severity, timing, and age of patient, among other factors. One significant factor in the pathology has consistently been …

Puberty-Associated Changes In Kiss1r, Mc3r, And Mc4r In The Ewe, Ashleigh Caitlyn Thomson

Graduate Theses, Dissertations, and Problem Reports (ETD)

The neural mechanisms that control the onset of puberty are not completely understood. In livestock, the onset of puberty relies on an increase in gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH). Kisspeptin, neurokinin B, and dynorphin neurons (KNDy) and their receptors, Kiss1r, NK3R, and KOR, respectively, are important regulators of puberty. Previous data from our laboratory has shown that KNDy neurons may be responding to other inputs, including the melanocortin system, that will affect the timing of puberty. Given this, we examined kisspeptin receptor (Kiss1r) mRNA expression in GnRH neurons as well as examining melanocortin 3 and 4 receptor …

Estradiol’S Role In Timely Puberty Onset In The Ewe, Eliana Gerardine Aerts

Graduate Theses, Dissertations, and Problem Reports (ETD)

In female sheep, the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus triggers luteinizing hormone (LH) to be released from the pituitary. Luteinizing hormone, in turn, acts on the ovaries to elicit estradiol (E₂) release. E₂ acts in a negative feedback manner to control the amount of LH released. The increase in LH release that drives puberty onset results from a decrease in sensitivity to E₂ as the animal ages. However, the neural mechanisms mediating this change in sensitivity are not known, as is where in the hypothalamus E₂-negative feedback occurs. In the arcuate …

Cell-Type-Specific Effects Of Synaptic Zinc In Mouse Auditory Cortex, Mason Mccollum

Graduate Theses, Dissertations, and Problem Reports (ETD)

Synaptic zinc signaling modulates synaptic activity and is present in specific populations of cortical neurons, suggesting that synaptic zinc contributes to the diversity of intracortical synaptic microcircuits and their auditory tuning properties. Stimulus-specific adaptation is a hallmark of sensory processing in which a repeated stimulus results in diminished successive neuronal responses, but a deviant stimulus will still elicit robust responses from the same neurons. Recent work has established that synaptically released zinc is an endogenous mechanism that shapes neuronal responses to sounds in the auditory cortex. Here, to understand the role of zinc signaling in the auditory cortex and the …

Structural And Functional Consequences Of Pde6 Prenylation In Rod And Cone Photoreceptors, Faezeh Moakedi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Phosphodiesterase-6 (PDE6) serves as a pivotal component in the phototransduction pathways of both cone and rod photoreceptors. In cones, PDE6 consists of tetrameric subunits: inhibitory (γ') and catalytic (α'). The catalytic subunit, PDE6α', contains a C-terminal prenylation motif. Deletion of this motif is associated with achromatopsia (ACHM), a form of color blindness. The mechanisms underlying the disease and the roles of PDE6 lipidation in vision remain elusive. Meanwhile, rod PDE6 is composed of α and β catalytic subunits and γ inhibitory subunits, with alterations in the C-terminal "prenylation motif" of PDE6β linked to retinitis pigmentosa (RP) pathology. In this comprehensive …

An Inhibitory Recurrent Network In The Olfactory System, Farzaan Salman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulatory circuits are a necessary component of neural flexibility as they are able to act differentially depending on the receptors expressed by their downstream targets. Identifying the synaptic partners of modulatory neurons and determining the neurotransmitter and receptor content of these partners is necessary to identify the rules governing neuromodulatory circuits. In this study, I characterized the circuit of the contralaterally projecting, serotonin-immunoreactive deutocerebral neurons (CSDns), the sole synaptic source of the neuromodulator serotonin in the olfactory circuit of Drosophila melanogaster, by identifying the strongest synaptic partners of the CSDns, and the expression of genes encoding neurotransmitters and receptors of …

The Effect Of Pubertal Stress On Prefrontal Cortex Related Behavior In Adult And Adolescent Mice, Bryan Rodriguez

Graduate Theses, Dissertations, and Problem Reports (ETD)

The prefrontal cortex (PFC) is an area of associated with cognitive flexibility, decision making, and value processing. The most common neuropsychiatric disorders globally, including generalized anxiety disorder, major depressive disorder, schizophrenia, and substance abuse disorders, have been associated with dysfunction in the PFC. One of the environmental factors that may lead to increased risk for developing these disorders is exposure to stressful or traumatic situations during key developmental periods, such as adolescence. Human studies found that individuals who were faced with early adverse events but had some form of social interaction or support during that time, had a lower risk …

Investigation Of Regulator Of G Protein Signaling-12 (Rgs12) As A Modulator Of Monoamine Transporters And Behavioral Responses To Cocaine, Allison Noel White

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stimulant use disorder is a psychiatric illness that is characterized by repeated use of stimulant drugs despite harm to the user. There are currently no Federal Drug Administration (FDA)- approved medications for stimulant use disorder, and the number of stimulant use-associated deaths have increased over the past decade. Given the prevalence of and lack of treatments for stimulant use disorder, there is an urgent need to identify new drug targets and treatments for this illness. Our group is investigating Regulator of G protein Signaling-12 (RGS12) as one such potential drug target for stimulant use disorder. Mice lacking RGS12 are insensitive …

Artificial Light At Night Disrupts Pain Behavior And Cerebrovascular Structure In Mice, Jacob Raymond Bumgarner

Graduate Theses, Dissertations, and Problem Reports (ETD)

Artificial Light at Night Disrupts Pain Behavior and Cerebrovascular Structure in Mice

Jacob R. Bumgarner

Circadian rhythms are intrinsic biological processes that fluctuate in function with a period of approximately 24 hours. These rhythms are precisely synchronized to the 24- hour day of the Earth by external rhythmic signaling cues. Solar light-dark cycles are the most potent environmental signaling cue for terrestrial organisms to align internal rhythms with the external day. Proper alignment and synchrony of internal circadian rhythms with external environmental rhythms are essential for health and optimal biological function.

The modern human environment on Earth is no longer …

Sense And Sensitivity: Spatial Structure Of Conspecific Signals During Social Interaction, Keshav Ramachandra

Graduate Theses, Dissertations, and Problem Reports (ETD)

Organisms rely on sensory systems to gather information about their environment. Localizing the source of a signal is key in guiding the behavior of the animal successfully. Localization mechanisms must cope with the challenges of representing the spatial information of weak, noisy signals. In this dissertation, I investigate the spatial dynamics of natural stimuli and explore how the electrosensory system of weakly electric fish encodes these realistic spatial signals. To do so In Chapter 2, I develop a model that examines the strength of the signal as it reaches the sensory array and simulates the responses of the receptors. The …