MS, Kent State University, 2025, College of Arts and Sciences / Department of Biological Sciences

The experiments presented in this thesis aimed to clarify the role of Oxtr signaling in the development of the RMS, as measured with DCX immunostaining, in both embryonic and adult mice. The data did not support the hypothesis posed that Oxtr disruption would lead to significant changes in neurogenesis. There are opportunities to improve on these experiments, mainly including increasing sample sizes. Furthermore, the variability in DCX expression and unexpected higher DCX levels in the olfactory bulb reaffirm the complexity of neurogenesis, and how it is potentially influenced by compensatory mechanisms in the absence of Oxtr. Although the results did not reveal significant differences in RMS or OB neurogenesis, they highlight the importance of investigating how transient Oxtr signaling disruptions affect the brain. Previous studies from our lab and others have shown that OxtrA treatment impairs social behavior in mice. Therefore, this work aimed to determine whether such disruptions influence neurogenesis in regions like the RMS, which is critical for supplying progenitor cells to the OB. Given the established role of the OB in modulating social behaviors, assessing the development of the RMS was a logical first step. While the findings suggest that RMS development remains unaffected, this opens the door to future investigations into other brain areas where changes might occur regarding neurogenesis and gliogenesis, ongoing areas of focus in our lab. Expanding this work to include behavioral studies and other neurogenic regions will provide deeper insights into the neural mechanisms underlying Oxtr function and its broader implications for brain development and plasticity.

Bachelor of Sciences, Ohio University, 2024, Biological Sciences

Fat-specific protein 27 (FSP27) plays a key role in regulating lipid metabolism in both adipose tissue and skeletal muscle (SkM) function. Emerging evidence suggests a link between SkM health and cognitive function, leading us to hypothesize that FSP27 might significantly impact neurocognition. To test this hypothesis, we utilized SkM-specific FSP27-knockout (Fsp27-/-) and SkM-humanized FSP27-transgenic (M-hFSP27tg) mouse models, representing loss- and gain-of- function of FSP27 in muscle, respectively. Behavioral assessments, including the Morris Water Maze and the Classic Labyrinth maze, were conducted to evaluate the effects of FSP27 manipulation on spatial memory, executive function, and motor coordination. Our results revealed that MhFSP27tg mice demonstrated superior cognitive performance, with enhanced memory retention and accelerated learning curves, while M-Fsp27-/- mice exhibited impaired spatial memory and problem-solving abilities. These findings indicate a significant role for FSP27 in neurocognitive function, likely mediated by its influence on SkM metabolism and interaction with brain processes. This research underscores FSP27's potential in addressing the reciprocal relationship between SkM and cognition, with future studies planned to elucidate its molecular mechanisms in neurocognition.

Bachelor of Science, Wittenberg University, 2024, Biochemistry/Molecular Biology

Obsessive compulsive disorder (OCD) is a neuropsychiatric disorder in which individuals can suffer from obsession, compulsions, and uncontrollable thoughts. Current treatments for OCD are not effective for all individuals, but an over-the-counter drug, N-acetyl cysteine (NAC), has shown promising therapeutic effects for those affiliated with OCD. In a past behavioral study, mice were separated into groups and given NAC for one or three weeks and then given RU24969, which is a 5-HT1B serotonin receptor agonist that induces perseverative behavior, a common characteristic of OCD in mice. The mouse brains were then homogenized, mRNA was extracted, and cDNA was created. The Quantitative Polymerase Chain Reaction (qPCR) analysis was used to measure gene expression in six chosen genes: CNTN4, TNR, GRIK3, GRIA2, SLC6A4, and ADRA2A and two reference genes. Gene expression was measured in seven different treatment groups with varying conditions including normal mice, those with OCD like symptoms, and those treated with NAC. These genes are involved in the nervous system in some way, which could mean there is a link between their activity and OCD. The trend in the data for these genes showed significant increases in gene expression in the 1-week NAC + water treatment and decreases in the 3-week NAC + RU treatment.

Master of Science in Biomedical Engineering (MSBME), Wright State University, 2024, Biomedical Engineering

This research explores how motor neurons (MNs) and Kv2.1 clustering change with age, emphasizing sex differences and MN subtypes. We found that MN density decreases with age in both sexes, while soma size increases in male mice. FF MNs were the most affected, and old weak mice had smaller MNs than their stronger counterparts, underscoring FF MN vulnerability. Baseline studies revealed that FF and FI MNs have larger Kv2.1 clusters compared to FR and S MNs. Female mice had smaller, denser Kv2.1 clusters than male mice, suggesting less clustering in females. With age, Kv2.1 clusters grew larger but became less dense and intense, indicating increased clustering. Old weak mice showed even more pronounced clustering than strong ones, linking Kv2.1 changes to age-related weakness. These findings highlight the susceptibility of FF MNs to aging and position Kv2.1 clustering as a key factor in motor neuron function and age-related decline.

Master of Science (MS), Wright State University, 2024, Microbiology and Immunology

Calcium signaling is a crucial regulator in many cellular processes, from immune response modulation to gene expression and apoptosis. Here, I have investigated the dynamics of calcium entry pathways, namely, store-operated calcium entry and store-independent calcium entry using a variety of cell types such as Jurkat T cells, HEK-293 cells and murine macrophages. Using fluorescence calcium imaging and selective inhibitor compounds, I have investigated the contributions of Orai and related calcium channels to calcium entry in both immune and non-immune cell types. The results demonstrate the pharmacological modulation of store-operated and store-independent calcium entry, showing the ability of compounds such as AE-19, AE-10, and EL-113 to inhibit calcium entry. Experiments involving membrane depolarization with elevated potassium concentrations confirmed that calcium entry through the plasma membrane is membrane potential-dependent. My results highlight the medical relevance of these channels, especially in the process of tubular aggregated myopathy, immune regulation and cancer. My studies may lead to therapeutics targeting calcium signaling pathways relevant to immune and muscular disorders.

Master of Science in Biomedical Engineering (MSBME), Wright State University, 2024, Biomedical Engineering

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by motor neuron (MN) death resulting in paralysis and eventually death. ALS has greater prevalence in older populations sharing characteristics with aging like muscle weakness and MN type specific degeneration. MNs innervate skeletal muscles and control muscle contraction through their excitability which is altered in both conditions. C-Boutons are a cholinergic, excitatory synaptic input to MNs and have been studied in ALS and aging but have produced inconsistent findings and undesired gaps. We used immunohistochemistry to label mouse lumbar spinal cord and separate MN types. 60x imaging and automated analysis was performed providing robust 3D measurements. Our results presented similar findings between two ALS mutations with differing changes in a third mutation. We also show C-Bouton input with age undergoes sex and MN type specific reductions aligning with age-related weakness. Finally, we identify C-Bouton similarities and differences between ALS and aging.

Ed.D., Antioch University, 2024, Education

Leveraging the researcher's unique diverse cultural and educational background, this dissertation explores integrating social emotional learning (SEL) within an innovative pedagogy of “with ness” (PoW) towards planetary well-being in educational settings. The overarching purpose is to redefine educational strategies through SEL and PoW to advance planetary well-being in tertiary contexts. As such, this dissertation critically engages with three published articles authored during the researcher's doctoral tenure to highlight transformative SEL practices that are fundamentally attuned to ecological consciousness. Informed by critical theory, feminist perspectives, and process philosophy, the hermeneutic circle reflects on these articles to address complex 21st-century challenges educational systems face such as technological disruption, language and culture diversity, mental health and emotional awareness amidst global scale events. Ultimately, the research from this project suggests there is further potential for SEL to contribute significantly to an educational and eventual societal shift that prioritizes planet Earth. By centering planetary well-being, this dissertation aims to help the researcher and readership gravitate towards a more empathetic, equitable, and ecologically conscious generation. This dissertation is available in open access at AURA (https://aura.antioch.edu) and OhioLINK ETD Center (https://etd.ohiolink.edu).

PhD, University of Cincinnati, 2024, Medicine: Molecular, Cellular and Biochemical Pharmacology

The nociceptive circuits of the body undergo large developmental changes postnatally that can be influenced by noxious stimuli. Chronic stress in early developmental windows can create maladaptive states for nociceptive transmission throughout the sensory circuits. The dorsal root ganglia (DRG) and the superficial dorsal horn (SDH) are major areas for transmission and modulation of sensory inputs through complex circuits of heterogenous neuronal populations. High levels of corticosterone (CORT) and activation of mineralocorticoid and glucocorticoid receptors (MR/GR) seem to influence acute and long-term changes of pain sensitivity within the body. Yet, it is unclear how resulting exposure to stress can change the functional properties of neuronal populations during these critical developmental time windows within these important areas that result in changes in pain sensitivity. Therefore, our general hypothesis is that chronic stress and CORT exposure contributes to changes in functional properties of neurons within the DRG and SDH that can modulate acute and long-term nociceptive transmission. We initially determined the distribution of MR and GR within the adolescent SDH. Following up with the neuronal firing and synaptic transmission in excitatory and inhibitory interneurons after acute and long-term CORT application. Overall, MR and GR was distributed throughout both neuronal populations. Acute CORT had reduced excitation in the SDH that was partly mediated by MR. Conversely, long-term exposure to CORT had sex-dependent mechanisms of actions with increased glutamate release onto neurons in males and reduced GABA/glycine responses in neurons of females. This could indicate duration of CORT exposure could provide analgesia or have sex-dependent mechanisms driving excitation and therefore pain transmission in this area. There are no studies on how chronic stress affects neonatal somatosensation and the immature DRG. Therefore, we investigated various (open full item for complete abstract)

Doctor of Philosophy, Case Western Reserve University, 2025, Biomedical Engineering

This dissertation focuses on non-perceptual effects of artificial sensation measured by effects in the motor system. Tactile feedback is used throughout the brain, from the “highest” cortical level to the “lower” spinal or brain stem level. Touch is first used before perception, or pre-perceptually, by the brain stem in simple, automatic modulation of the motor system. For example, carrying an object from place to place or even shifting it in one's hand involves many changing tactile signals. Even a single ridge of a fingertip supplies a unique signal for use in object manipulation. If one had to actively perceive and act upon all this information, merely picking up an object would become overwhelming. Fortunately, the lower levels of our brain automatically make minor adjustments to grip based on tactile information. What is not known is how relevant perceptual qualities are to these automatic corrections to grip. The cortex, not the brainstem, is the location of tactile perception, so it stands to reason that the brainstem does not require “natural” qualities of tactile feedback. Our lab has a group of participants with peripheral nerve cuff electrodes we can stimulation through. We tested how well artificial tactile feedback would integrate with the sensorimotor system in tasks of increasing complexity. We found that peripheral nerve stimulation is processed similarly to naturally generated touch with and without perception and may engage with the motor system as seen by the intent to modulate grip force.

Master of Arts, Miami University, 2024, Spanish

El estudio propuesto de comparacion replica inversa incorporara la linguistica aplicada, la transferencia ritmica y la adquisicion del espanol como L2 por los hablantes adultos nativos del ingles americano como L1 en la universidad. Las medidas ritmicas de ΔC, %V, ΔV, CrPVI y VnPVI se utilizaran para determinar la duracion silabica, vocalica y consonantica exhibida por el ingles frente al espanol. Una comparacion de las mediciones duracionales pondra de manifiesto la presencia y el grado de transferencia ritmica exhibida. El objetivo del estudio propuesto es destacar las diferencias segmentarias entre una lengua silabica frente a una lengua acentual como evidencia empirica de transferencia ritmica. Los resultados de un estudio previo del gallego como L1, una lengua silabica, y el ingles britanico como L2, una lengua acentual, de Rodriguez-Vazquez y Roseano (2022), muestran que el grado de transferencia linguistica que se exhibe, depende del nivel de competencia alcanzado, asi como la experiencia de estudiar en el extranjero. Se exploraran otros factores que podrian afectar la transferencia ritmica, como el numero de idiomas que se hablan. Finalmente, los resultados del estudio propuesto (del ingles-L1/espanol-L2) se compararan con los resultados del estudio anterior (del gallego-L1/ingles-L2) para un analisis comparativo posterior. El estudio propuesto de comparacion replica inversa incorporara la linguistica aplicada, la transferencia ritmica y la adquisicion del espanol como L2 por los hablantes adultos nativos del ingles americano como L1 en la universidad. Las medidas ritmicas de ΔC, %V, ΔV, CrPVI y VnPVI se utilizaran para determinar la duracion silabica, vocalica y consonantica exhibida por el ingles frente al espanol. Una comparacion de las mediciones duracionales pondra de manifiesto la presencia y el grado de transferencia ritmica exhibida. El objetivo del estudio propuesto es destacar las diferencias segmentarias entre una lengua silabica frente a una le (open full item for complete abstract)

Master of Science, The Ohio State University, 2024, Health and Rehabilitation Sciences

Background: Individuals with Huntington's disease (HD) with balance and gait impairments experience falls, which often leads to injuries and reduced quality of life. Therefore, clinicians need to identify individuals who are at risk of falling to prescribe appropriate fall prevention strategies. Objectives: This study investigated the ability of a variety of clinical balance and gait assessments to differentiate between fallers and non-fallers and the accuracy of each assessment to determine fall risk. Methods: Thirty-three individuals with diagnosed HD were recruited for the study (18 retrospectively identified fallers and 15 non-fallers). Each participant was evaluated with three categories of scales: HD-specific scales (Unified Huntington Disease Rating Scale total motor score [UHDRS-TMS] and UHDRS-TMS balance and gait subitems (i.e., gait, tandem walk, and retropulsion pull test), balance specific scales (Mini Balance Evaluation System Test [Mini-BESTest] and the Activities-Specific Balance Confidence Scale [ABC Scale]), and functional gait scales (Community Balance and Mobility Scale [CBM] and Functional Gait Assessment [FGA]). Results: The discriminant function analysis determined that the best discriminators of faller or non-faller group memberships were the Mini-BESTest, CBM and the UHDRS-TMS balance and gait subitems. Receiver operating characteristic (ROC) curve was used to determine the best fall risk cutoff score. The highest three clinical tests had an area under the curve and a corresponding cut off score as follows: Mini-BESTest (0.774, ≤19/28), CBM (0.761, ≤37/96), and the UHDRS-TMS balance and gait subitems (0.728, ≥4/12). The odds ratio for the Mini-BESTest, CBM, and UHDRS-TMS balance and gait subitems were 7, 10.21, and 11.2, respectively. Using a pretest probability of 54%, and a positive likelihood ratio, the posttest probability changes were Mini-BESTest (73.2%), CBM (84.3%), and the UHDRS-TMS balance and gait subitems (88.6%). Con (open full item for complete abstract)

Doctor of Philosophy (PhD), Ohio University, 2024, Translational Biomedical Sciences

The global population is rapidly aging, creating a significant public health challenge as aging is associated with a myriad of health concerns, including an increased prevalence of osteoporosis, cardiovascular disease, and neurodegenerative conditions such as Alzheimer's and Parkinson's disease. Additionally, aging often threatens independent living, as adults over age 60 are more likely to experience muscle weakness, reduced mobility, difficulties with activities of daily living, and a higher incidence of falls. To address these aging-related health crises, the field of geroscience has shifted focus toward capturing the hallmarks of biological aging, with the goal of mitigating physiological processes that contribute to functional decline. Among the emerging biomarkers of aging, biological brain age—derived from neuroimaging techniques and machine learning models—has shown great promise as an indicator of global brain health. By comparing brain age to chronological age, one can assess the rate of brain aging, with accelerated brain aging (brain age > chronological age) linked to several conditions, including Alzheimer's disease, schizophrenia, cognitive impairments, and slower gait speed. I conducted preliminary cross-sectional analyses and leveraged data from the Baltimore Longitudinal Study of Aging (BLSA), a large, well-characterized longitudinal dataset, to examine the complex relationships between brain aging, muscle strength, and physical function. I found that accelerated brain aging was associated with slower gait speed, longer time to complete five consecutive chair stands, and difficulty completing a narrow walking task, demonstrating brain age's predictive value for physical function. Moreover, I identified a relationship between an accelerated rate of brain aging and elevated levels of interleukin-6 (IL-6), a pro-inflammatory cytokine implicated in inflammaging—the chronic, low-grade systemic inflammation observed in older adults. To further explore the (open full item for complete abstract)

PHD, Kent State University, 2024, College of Arts and Sciences / School of Biomedical Sciences

Opioid addiction and opioid use disorder (OUD) is one of the major problems that we are facing not only in the US but all around the world. An estimated 3 million US citizens and 16 million people worldwide suffer from OUD by 2022. This number is expected to keep rising in the coming years. One of the leading causes of death related to OUD is opioid-induced respiratory depression (OIRD), in which overdose is accompanied by into respiratory arrest; the individual can die if not treated promptly. Currently, the only approved treatment modality for OIRD is a drug known as naloxone which is administered by emergency personnel to an individual who has overdosed on opioids and is suffering from OIRD. Naloxone as a drug also has its own issues like a short half-life; this precipitates withdrawal and blocks the analgesic effects of opioids. One of the major problems associated with naloxone is the potential need for repeated administration of higher doses to counter the effects of fentanyl and its analogs at the epicenter of this epidemic. This has made it necessary for development of new more efficient drugs with lesser side effects to counter this epidemic. Neuronal signaling from the superior cervical ganglion (SCG) is shown to modulate respiratory dynamics at least in part. The aim of this study was to deduce the effect of a novel thiol ester D-Cysteine ethyl ester (D-CYSee) on fentanyl-mediated effects on intrinsic Ca2+ activity in the SCG and to determine how it compares to naloxone. We used real-time Ca2+ imaging to deduce changes in intrinsic Ca2+ activity in response to voltage-gated Na+ and Ca2+ channel blockersand naloxone in presence and absence of fentanyl, and D-CYSee in presence and absence of fentanyl in cells isolated from the SCG. Key outcomes from our studies show that 1) cells receiving drug-free control treatment showed consistent activity and extracellular Ca2+ was key for the activity; 2) the activity was driven primarily by L-type calcium channels a (open full item for complete abstract)

Doctor of Philosophy, Miami University, 2024, Biology

This dissertation investigates the sexually dimorphic expression of the nos gene, which encodes for the enzyme Nitric oxide synthase (NOS). NOS activation produces the gaseous signaling molecule nitric oxide (NO), which can impact immune function and behavior. Despite the crucial role of NO in insect physiology, the mechanisms underlying nos expression in both sexes and in different social environments remain poorly understood. Our primary aim was to elucidate the impact that a lack of social interaction can have on nos expression and immune function, providing new insights into insect physiology and behavior. We cloned and characterized the Ad-nos gene, revealing a close phylogenetic relationship with other orthopteran insects. Quantitative PCR analysis showed that early adult females exhibited significantly higher Ad-nos expression in nervous and thoracic fat body tissues than males, while males had higher expression in hemolymph. Following lipopolysaccharide (LPS) injection, males showed increased Ad-nos expression in brain and hemolymph, whereas females showed elevated expression in fat bodies and hemolymph. These findings suggest sex-specific immune strategies, with males prioritizing cellular immunity and females employing both humoral and cellular responses. We also examined the effects of social interaction during different developmental stages on NO levels and immune function. Comparing adult-isolated and nymph-isolated crickets, we found significant sex-dependent differences in Ad-nos expression. Nymph-isolated females had higher Ad-nos expression in brain and hemolymph, while nymph-isolated males showed higher expression in brain fat body and thoracic fat body tissues. NO activity assays indicated lower activity in nymph-isolated crickets compared to adult-isolated crickets. In addition, nymph-isolated females had fewer circulating hemocyte than males, while males had higher hemolymph protein content. Survival analysis post-LPS injection showed that adult (open full item for complete abstract)

Doctor of Philosophy, Case Western Reserve University, 2025, Biomedical Engineering

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting adults with hallmark motor symptoms. Recent research has however shown it to be a multifaceted disorder with a myriad of non-motor symptoms. Eye movement deficits are an under-recognized and less understood symptom in PD, affecting at least half of the PD population in some form. Differentiating PD-related ocular motor deficits from age-related or congenital abnormalities presents significant challenges. Recent research has established a relationship between PD and ocular motor dysfunction, revealing that the pathological firing from the basal ganglia circuitry, where PD originates, disrupts the pathways controlling ocular motor behavior. This study delineates three primary ocular motor deficits in PD: vergence, saccades, and fixational stability or strabismus. Vergence is impaired by decreased gains, altered trajectories, and decreased fusion maintenance, leading to difficulties in maintaining binocular vision. Saccadic movements show decreased conjugacy, increased latencies, and slower trajectories, resulting in less accurate and coordinated eye movements. Fixational instability is observed as 12 increased exodeviation and an increased angle of strabismus, which further compromise visual stability. Additionally, our research explores the impact of therapeutic interventions on ocular motor behavior in PD. Deep brain stimulation (DBS), commonly used to manage motor symptoms such as tremor and rigidity in PD, also alters ocular motor function. Unlike levodopa, which produces no effect on OMD, DBS was shown to influence fibers in the ocular motor network. In 75% of cases with recognized PD-related ocular motor deficits, DBS improved vision-related quality of life to varying extents. However, the benefits of DBS on ocular motor responses depend on the specific location and region of stimulation, with some configurations potentially exacerbating the deficits. This (open full item for complete abstract)

Doctor of Philosophy, Northeast Ohio Medical University, 2024, Integrated Pharmaceutical Medicine

Alzheimer's disease (AD), the leading cause of dementia, is a worldwide public health issue that is getting progressively worse as the population ages. AD is a neurodegenerative disorder characterized by its progressive and ultimately fatal nature. Surprisingly, the biological onset of the disease can occur decades before the emergence of observable symptoms. Despite ongoing research and clinical trials, effective disease-modifying treatments for AD remain elusive, with most of the investigative focus being on one of the two key pathological proteins of this disease, amyloid beta (Aβ). The other protein, pathological tau, has been comparatively understudied even though it has been observed to precede Aβ deposition in the early stages of dementia and exhibits a stronger correlation with cognitive decline as the disease progresses. Several key factors are associated with increased AD risk with the most influential including female sex and midlife onset of cardiometabolic stressors such as type II diabetes, obesity, hypertension and hyperlipidemia. Irisin and VGF are two endogenous hormones known to mitigate the impact of these key midlife AD risk factors and their levels in blood and brain potentially serve as biomarkers for the disease. Both irisin and VGF have been examined as neuroprotective therapeutics against AD pathology such as Aβ and neuroinflammation but have not been investigated in the context of tauopathy. The work presented in this dissertation addressed a central hypothesis that VGF and irisin can mitigate tau pathogenesis and disease progression. Overall, the data collected from these studies support this hypothesis but also introduce many unexpected nuances and additional variables that qualify the conclusions on the neuroprotective potential of these agents in tauopathy. Here, I found that exogenous irisin treatment administered to tauopathy model htau mice at presymptomatic disease stages mitigated emerging neuropathology in only female mice. Wh (open full item for complete abstract)

Doctor of Philosophy, Case Western Reserve University, 2024, Chemistry

Free radical-induced oxidation of lipids generates a vast array of molecules. One of these is a phospholipid ester of 8-oxo-4-hydroxyoct-2-enoic acid. A chemical mechanistic hypothesis suggested that conjugation of this a,b-unsaturated aldehyde with glutathione could lead to the formation of a molecule, which we named pseudo leukotriene (øLT)C, that bears structural and functional resemblance to leukotriene LTC4. Catabolism of LTC4 to a glycyl cysteine derivative LTD4 and of LTD4 to a cysteine derivative LTE4, suggested that øLTC would be catabolized to produce a glycyl cysteine derivative øLTD and then a cysteine derivative øLTE. Because LTE4 is acetylated in the kidneys and excreted in urine, the production of N-acetyl-øLTE in vivo was also postulated. To test these hypotheses, total syntheses of øLTs and N-acetyl-øLTE were performed. In ten steps, a divergent strategy generated each øLT from a single precursor, ethyl glutaryl chloride. Because two diastereomers were expected to be generated in the Michael addition of a thiol and the reduction of a ketone, each synthesis is expected to produce four enantiomers. Pure samples are especially important for testing the biological activities of øLTs. Therefore, HPLC methodology was developed that provided pure samples, as diastereomeric mixtures, of all synthetic øLTs. The ethyl ester intermediates øLTE-OEt could be separated into two pure diastereomers and a mixture of two other diastereomers, confirming that the syntheses are non-diastereoselective. Heavy isotope derivatives were also prepared and used to develop LC-MS/MS analyses to facilitate the detection, structural characterization, and quantitation of øLTs in vitro and in vivo. The Salomon group exploited these HPLC pure samples of øLTs to determine their production and biological activities in vitro and in vivo. In a pilot model study of Alzheimer's disease, I demonstrated that exposure of differentiated human neuronal SH-SY-5Y cells to the Ab1-42 peptid (open full item for complete abstract)

Doctor of Philosophy, Case Western Reserve University, 0, Neurosciences

Transcription factors orchestrate the expression of cell-type specific transcriptomes throughout brain development, generating immense cellular diversity. Hundreds of pathogenic mutations have been identified in neuronal transcription factors, but few studies have investigated their impact. LMX1B is a continuously expressed terminal selector-type transcription factor indispensable for the acquisition and maintenance of serotonin (5-HT) identity and morphology. Over 200 different pathogenic LMX1B mutations have been identified in humans, but their impact on brain development is unknown. In this dissertation, I utilized CRISPR/Cas9 to generate two novel mouse models carrying distinct pathogenic DNA-binding LMX1B missense mutations in order to study their epigenetic and architectural consequences. Heterozygous Lmx1b missense mutations uniquely disrupted the expression of hundreds of genes throughout the serotonergic transcriptome. Differentially expressed genes were enriched with synapse, axon, and mitochondrial related functions. These changes were correlated with a highly specific defect in postnatal 5-HT arborization without disrupting embryonic axonal development. Both missense mutations caused similar arborization defects within the hippocampus and motor cortex, but had distinct impacts on the striatum. Hippocampal fiber loss was associated with spatial memory defects. Digital Genomic Footprinting (DGF) revealed that missense heterozygosity caused a spectrum of effects on Lmx1b activity, ranging from a total loss to a partial gain. These footprints were likewise associated with synapse, axon, and mitochondrial related genes. Missense heterozygosity further disrupted the activity of transcription factors within Lmx1b-dependent regulatory networks. This study is the first to demonstrate the severe consequences of pathogenic LMX1B mutations on serotonin development, while highlighting the utility of using DGF to unveil the complex effects of missense heterozygosity (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2024, Neuroscience Graduate Studies Program

Background: Paternal deprivation is a significant early-life stressor with long-lasting effects on social behaviors and physiology. This series of studies investigates the extent to which paternal deprivation induces social impairments, alters corticosterone (CORT) reactivity, and affects central and peripheral immune responses in adult male and female offspring. We also examine the need for more research on the impact of paternal absence on offspring. Chapter 2 Hypothesis: Paternal deprivation induces social impairments, alterations in CORT reactivity, and changes in central immune response to acute stress in adult male and female offspring. Methods: We assessed the effects of paternal deprivation on social behaviors, CORT reactivity, and central immune response in adult California mice. Social behavior was evaluated using a novel same-sex and age-matched conspecific. CORT reactivity was measured following an acute physical stressor and central proinflammatory cytokine response was analyzed. Results: Paternal deprivation led to vigilant-avoidant social behavior in both male and female offspring, with social vigilance persisting in females but not in males. Paternally-deprived females exhibited reduced CORT reactivity, while males showed altered central proinflammatory cytokine response. Conclusion: These findings indicate that paternal deprivation induces more pronounced social impairments in female offspring, potentially mediated by sex-specific neurobiological mechanisms. Chapter 3. Hypothesis: Paternal deprivation results in sex-specific changes in social behaviors and basal neuroimmune function in adult offspring. Methods: A 30-minute social preference test was conducted to evaluate changes in social behaviors and social risk assessment strategies in paternally-deprived male and female California mice. Neuroinflammatory-related genes were assessed using NanoString nCounter technology to determine basal neuroimmune function. Results: Independent of rearing exper (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2024, Neuroscience Graduate Studies Program

Women are over twice as likely to develop stress-induced affective disorders, including anxiety disorders and major depressive disorder, than men, however this sex difference in prevalence does not emerge until pubertal onset. This suggests that there may be a role for ovarian hormones in organizing stress-sensitive brain circuitry during adolescence to increase female vulnerability to stress. Our lab had previously identified female prefrontal parvalbumin (PV) interneurons as sensitive to stress in a sex-specific manner, with increased expression and activation of prefrontal PV+ cells being associated with increased anxiety-like behavior following four weeks of chronic stress. Furthermore, we have found that activation of PV+ interneurons in the absence of stress is sufficient to induce anxiety-like behavior in female, but not male, mice, however the mechanism underlying this sex-specific stress sensitivity remained unknown. In this work, I aimed to characterize the mechanism modulating the sexual dimorphism of prefrontal parvalbumin (PV) interneuron stress sensitivity; and determine whether ovarian hormones at puberty contributed to the maturation of prefrontal PV+ interneurons and their stress-sensitive phenotype. First, we investigated whether the stress-sensitive phenotype of female prefrontal PV+ interneurons could be induced in male mice using a longer period of chronic stress or chemogenetic activation of this cell population. While exposure to a longer period of unpredictable chronic mild stress did lead to stress-induced increases in anxiety-like behavior in male mice, this outcome could not be achieved by directly stimulating prefrontal PV+ interneurons, suggesting that the stress sensitivity of prefrontal PV+ interneurons in females and associated increased anxiety-like behavior cannot be induced and is instead unique to females. Next, we aimed to determine the functional relevance of pubertal ovarian hormones in driving stress sen (open full item for complete abstract)