Molecular and Cellular Neuroscience Commons^™

Investigation Of Motor Neuronal And Circuit Level Mechanistic Determinants Of Spinal Excitability Following Cst Injury, Thelma Bethea

Dissertations, Theses, and Capstone Projects

The corticospinal tract (CST) is the primary descending motor pathway in mammals, essential for precise, dexterous movements, especially in humans and nonhuman primates. Damage to the CST, such as from spinal cord injury (SCI), impairs skilled motor function and triggers maladaptive changes including aberrant proprioceptive afferent sprouting and increased spinal excitability. These changes are closely linked to both muscle weakness and the development of hyperreflexia, compounding the functional deficits. Animal models of SCI are valuable for investigating mechanisms of injury and recovery, though traditional models often limit the ability to isolate circuit-specific contributions. To address this, I employed selective unilateral …

The Sonic Hedgehog Effector Smoothened Modulates Cholinergic Interneuron Activity, Physiology, And Striatum-Dependent Behaviors, Santiago Uribe-Cano

Dissertations, Theses, and Capstone Projects

The striatum is a central node in action selection and associative learning, integrating cortical, thalamic, and neuromodulatory input. Among its principal modulators, dopamine (DA) and acetylcholine (ACh) are known for their temporally coordinated yet mechanistically distinct influences on striatal output. However, the upstream signals that regulate their dynamic interplay, particularly within cholinergic interneurons (CINs)—the primary source of striatal ACh—remain incompletely characterized. This dissertation investigates the role of Smoothened (Smo), a G protein-coupled receptor (GPCR) effector of Sonic Hedgehog (Shh) signaling, in modulating ACh signaling dynamics in the striatum.

Building on evidence that midbrain DA neurons co-release Shh and that CINs …

Mechanistic Insights Into The Neuroprotective Effects Of The Antidepressant Agomelatine In Alzheimer's Disease, Grace Terry

Dissertations, Theses, and Capstone Projects

Alzheimer’s Disease (AD) is a complex neurodegenerative disease that has limited treatment options and no cure. AD is characterized by robust pathology including extracellular amyloid beta plaques, intracellular neurofibrillary tangles, neuronal and synaptic loss, neuroinflammation, and brain atrophy. AD presents with cognitive decline and memory loss but only years after neuropathology has started to accumulate. This robust pathology has made AD difficult to treat and highlights the need for therapeutics that modulate multiple pathways. Agomelatine (AGO) was selected by a high-throughput machine learning drug repurposing algorithm by our collaborator Dr. Lie Xie (Hunter College Dept. of Comp. Sci.) as having …

Repurposing Atractylenolide Iii, A Natural Anti-Inflammatory Compound, For Alzheimer’S Disease, Angela M. Steele

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is a debilitating neurological condition ranked as the fifth leading cause of death in adults over the age of 65. Despite the severity, 98% of drugs have failed as treatments for AD. Current novel drug development approaches have been unable to produce a disease-modifying treatment as they often have a one-target approach, not accounting for the complex nature of the disease. One of the hallmarks of the disease, inflammation, may provide a better target for treatment because it interacts with multiple facets of the disease. Drug repurposing to identify compounds that mitigate inflammation in AD could provide …

Detecting Sonic Hedgehog Expression In The Adult Mouse Brain Using A Gene Expression Tracer, Kendra Stephens-Jones

Dissertations, Theses, and Capstone Projects

Sonic Hedgehog (Shh) is best known for its role in development, yet evidence supports Shh signaling plays a functional role in the adult brain. Previous work demonstrated that Shh is expressed by dopamine (DA) neurons in the ventral midbrain and that loss of Shh from these neurons leads to late-onset motor and structural abnormalities resembling Parkinson’s disease. However, the extent of Shh expression and its connectivity to the striatum in the adult mouse brain remain unclear due to the lack of reliable antibodies for Shh detection. To address this gap, the present study employed Shh ^L/L and DAT-Cre^+/- mice …

The Molecular And Behavioral Characterization Of The Murine Cre – Loxp Skeletal Muscle Synthesized Bdnf Knockout Model, Asha E. Rustad

All NMU Master's Theses

Brain derived neurotrophic factor (BDNF) is a neurotrophin essential for supporting the growth, differentiation, and health of neurons within the central and peripheral nervous systems. BDNF is also a member of the myokine family, where muscle synthesized-BDNF (msBDNF) is thought to facilitate the crucial bi-directional communication between the motor neuron and the muscle fibers it innervates. Since 2008, the Ottem Laboratory has investigated the role of msBDNF by employing Cre/LoxP recombinase technology to selectively delete the BDNF coding region within skeletal muscle of mice. This approach generates animals with either heterozygous or homozygous deletions of msBDNF, as well as BDNF …

Advanced Interactions Of Directed Energy With Retinal Pigment Epithelial Cells And Their Photochemical And Photothermal Responses, Jin B. Ha

Theses & Dissertations

Excess optical radiation can injure the retina through either rapid heat deposition (photothermal damage) or cumulative photo‑oxidative stress (photochemical damage), yet current laser‑safety limits treat these mechanisms as independent. To test that assumption, this dissertation integrated systematic wavelength, duration and temperature‑controlled laser exposures with live/dead fluorescence imaging in a melanin‑loaded hTERT‑RPE1 monolayer model. First, concurrent 447 nm (blue) and 2 µm (infra‑red) beams delivered for 200 s demonstrated a strong thermal–photochemical synergy: each beam alone was sub‑threshold (≤25 % lethality) but together produced 100 % RPE death without exceeding 50 °C, proving that modest heating markedly lowers the photon dose …

Aptamer Selection And Development Of Electrochemical Aptamer-Based Sensors For Neuropeptide Y, Evelyn Adela Carreto Guevara

Department of Chemistry: Dissertations, Theses, and Student Research

In this thesis, we report the results of four aptamers obtained from an aptamer selection process called the systematic evolution of ligands by exponential enrichment (SELEX) with affinity to Neuropeptide Y (NPY). NPY is a highly abundant peptide transmitter with widespread distribution throughout the body which affects various physiological functions. These functions include energy homeostasis, appetite regulation, stress response, and anxiety regulation. Dynamic monitoring of NPY levels is crucial for better understanding behaviors in individuals with neurological disorders associated with NPY. Aptamers are synthetic oligonucleotides obtained through SELEX which have a binding affinity to a target of interest when in …

Structural Functional Investigation Of Hap40, Amanda M. Solbach

Dissertations and Theses (Open Access)

STRUCTURAL FUNCTIONAL INVESTIGATION OF HAP40

Amanda Marie Solbach

Dissertation Advisor: Sheng Zhang, Ph.D.

Huntington’s disease (HD) is a devastating neurodegenerative disorder caused by an expanded CAG trinucleotide repeat in the Huntingtin (HTT) gene, resulting in a mutant huntingtin (mHTT) protein with an elongated polyglutamine tract. While the genetic basis of HD is well established, the mechanisms underlying mHTT toxicity and its impact on cellular function remain incompletely understood. Recent discoveries implicate Huntingtin-associated protein 40 (HAP40) as a critical regulator of HTT stability and intracellular function. However, the physiological and pathological significance of this interaction has not been fully explored.

This …

The Role Of Androgen Receptor And B2/Alu Sine Rna Interaction In Hippocampal Dendritic Development, Troy A. Richter

Graduate Doctoral Dissertations

Once dismissed as “junk”, transposable elements have recently gained recognition for their regulatory roles, especially in the brain. During development, circulating androgens promote proper morphological development of hippocampal neurons. We and others have shown that murine B2 SINE RNA is a regulator in the rodent hippocampus. It is unknown, however, if B2 is necessary for the proper development of hippocampal neurons. This dissertation investigates the role of murine B2 in the development of primary hippocampal neurons in combination with androgen treatment. We first examined the role of ALU SINE and androgen receptor in a prostate cancer cell model and found …

Investigating The Capacity Of Tdp-43 Low Complexity Domain To Target Protein Aggregates In Yeast, Nicholas J. Grahame

Biology Summer Fellows

Utilizing protein TDP-43 and fluorescent proteins to:

Investigate TDP-43’s LCD region in protein aggregates. Use fluorescent protein tagging to visualize co-localization and aggregation. Leverage yeast as a model system for studying LLPS and aggregation.

Can we target chaperone proteins to TDP-43 LCD region?

Alpha-Synuclein Null Mutation Exacerbates The Phenotype Of A Model Of Menkes Disease In Female Mice, Meganne Casey, Dan Zou, Renee Reijo Pera Phd, Tiffany Hensley-Mcbain, Deborah E. Cabin

Touro College of Osteopathic Medicine (Great Falls) Publications and Research

Human SNCA, which encodes a-synuclein protein (SNCA), was the first gene linked to familial Parkinson's disease (PD). Since the discovery of the genetic link of SNCA to Parkinson's nearly three decades ago, many studies have investigated the normal function of SNCA protein. However, understanding of the normal function of SNCA is complicated by the lack of a reliable mammalian model of PD; indeed, mice with homozygous null mutations in the Snca gene live a normal lifespan and have only subtle synaptic deficits. Here, we report the first genetic modifier (a sensitized mutation) of a murine Snca null …

Investigating The Role Of Msbdnf – Trkb Signaling In The Maintenance Of Mitochondrial Populations Through The Bnip3 Mitophagy Pathway, Jack A. Horton

All NMU Master's Theses

Maintenance of mitochondrial transport and clearance at the pre- and post-synaptic terminal is an essential function of neuromuscular junctions to meet their high energy demands. Damaged or dysfunctional mitochondria can put stress on these synaptic junctions, ultimately leading to the degradation of the synapse and subsequent cell death. Dysfunctional mitochondria are also often present in neuromuscular diseases such as ALS. One possible mechanism by which neurons may eliminate dysfunctional mitochondria is through the muscle-synthesized BDNF (msBDNF) /TrkB-mediated Bcl-2 nineteen-kD interacting protein (BNIP3) mitophagy pathway, although the relationship is not well-defined. BNIP3 localizes to the mitochondria and triggers a loss of …

Gardenia Jasminoides Extract As A Potential Neuroprotective Agent In An In Vitro Tauopathy Model, Inas Birekdar

Theses and Dissertations

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder marked by the selective loss of neurons in various brain regions, leading to cognitive dysfunction. Neurofibrillary tangles (NFTs), composed of hyperphosphorylated tau protein accumulate within neuronal cells leading to cell death. The development of effective treatments for neurodegenerative diseases (NDs) remains a significant challenge, with neuroprotection emerging as a promising therapeutic strategy to slow disease progression and preserve cognitive function.

Objective: This study aims to investigate the potential neuroprotective effect of Gardenia jasminoides fruit extract, which contains geniposide, a biologically active compound known for its neuroprotective properties, in mitigating Tau hyperphosphorylation in …

Analysis Of Synaptotagmin Isoforms In Lßt2 Gonadotrophs, Caitlin Vahl

Undergraduate Theses, Capstones, and Recitals

The anterior pituitary is comprised of five cell types which secrete regulatory hormones into the bloodstream. Specifically, gonadotrophs synthesize and release sex hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in response to gonadotropin-releasing hormone (GnRH). GnRH signals from the hypothalamus regulate the differential secretion of LH and FSH from the anterior pituitary. Exocytosis of FSH and LH from dense core vesicles (DCVs) occurs in response to an intracellular calcium signal, sensed by the synaptotagmins proteins. Various isoforms of synaptotagmins exist and each isoform has varying affinity for calcium, causing calcium-regulated exocytosis to be finely controlled. Because LH and FSH …

Topodino: Self-Supervised Topological Representation Learning For Neuronal Morphologies, Yasser Binbisher

Master's Theses

Neuronal cell types are categorized by transcriptomic identity, yet their morphological heterogeneity defies this classification. In response, researchers have adopted unsupervised graph representation learning as a tool to reveal morphological variation within single-class transcriptomic types. However, the complex geometry of neuronal morphology—especially long axons and dense dendrites—challenges graph neural networks, which struggle with message propagation across extended structures. To mitigate this, current approaches enforce sub-sampling on neuronal graphs and omit axons entirely, sacrificing critical biological features for computational efficiency. To overcome this trade-off, this thesis introduces TopoDINO, a self-supervised, topology-aware representation learning model designed to preserve the full hierarchical organization …

Parvalbumin Interneuron-Oligodendrocyte Interactions In The Infralimbic Cortex Promote Extracellular Plasticity Mechanisms After Safety Learning, Lucy Emma Denholtz

Dissertations, Theses, and Capstone Projects

The ability to differentiate between threat and safety cues is essential for adaptive behavior, yet this process is disrupted in psychiatric disorders, such as post-traumatic stress disorder (PTSD), where safety cues fail to downregulate fear expression. To better understand the neurobiological mechanisms of safety learning, I investigate how safety conditioning vs contextual fear conditioning modify behavioral and cellular mechanisms in the infralimbic (IL) region of the medial prefrontal cortex (mPFC) at several time points after learning. Through this work, I identify a novel mechanism whereby safety learning promotes learning dependent neuro-glial interactions that promote conditions for plasticity in the mPFC. …

Neural Mechanisms Of Context-Sensitive Behavior In The Adult Male Zebra Finch, Katherine L. Anderson

Dissertations, Theses, and Capstone Projects

Adapting behaviors to the perceived external environment is key to the success and survival of individuals in social species. This context-sensitive modulation of behavior is critical for informative interactions with conspecifics, like alerting a neighbor to a nearing predator or capturing the attention of a potential mate. For the adult male zebra finch (Taeniopygia guttata), a vocal-learning songbird, context-sensitive adaptions to a learned song are key for developing and maintaining pair-bonds with females who are extremely attentive to subtle modulations of song structure. In this thesis, I explore the hypothesis that the influence of a social behavior network …

Understanding How Genetic Mutations Induce Oligodendrocyte Progenitors To Become Cancer Cells, Dennis Huang

Dissertations, Theses, and Capstone Projects

Gliomas are the most devastating adult brain tumors characterized by poor survival rate and limited options for treatment. Previous studies have shown that they are very heterogeneous and can be further sub-classified based on their transcriptional signature and the presence of specific mutations. One such subtype, is the “proneural glioma”, which is characterized by the enrichment in oligodendrocyte progenitor cell (OPC) transcripts and mutations in genes encoding for the tumor suppressor P53 (Trp53) and for Platelet Derived Grow Factor (PDGF) signaling. Since OPCs are the most abundant proliferative population in the adult brain, in this …

Neuroinflammation In The Ventral Tegmental Area Of Chronically Stressed Rats, Marie M. Hafez

Honors Projects

Chronic stress has been associated with maladaptive behaviors in both human and animal research models, but the underlying mechanisms are unclear. In this research study, we sought to define whether stress induces neural inflammation in the ventral tegmental area, the brain region primarily responsible for regulating reward consumption, learning, memory, and addictive behaviors through moderating dopamine release in other brain areas. To do this, male Sprague-Dawley rats were subjected to a chronic intermittent stress paradigm that included stressors such as wet bedding, delayed feedings, social isolation, strobe lights, and forced swims. Following the chronic stress intervention, brain sections were collected …