Molecular and Cellular Neuroscience Commons^™

The Rpm-1/Phr Signaling Hub Modulates Tau-Induced Neurodegeneration Through Regulation Of Microtubule Stability And Mapk Pathways In C. Elegans, Xinxing Ding

Theses and Dissertations

Neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia, are characterized by the accumulation of pathological tau proteins and progressive neuronal loss. Although research regarding tau-mediated toxicity is extensive, the specific pathology that determine whether neurons maintain homeostasis or succumb to collapse under tau-induced stress remain incompletely elucidated. A central, yet still insufficiently understood, feature of these diseases is the disruption of the microtubule (MT) cytoskeleton . The PHR protein family is evolutionarily highly conserved; within this family, RPM-1 in C. elegans functions as an intracellular signaling hub that regulates axon development, synapse formation, axon termination, and various microtubule-associated processes. This …

Establishment Of A Hek293t Cell Model System To Investigate Direct Intracellular Interactions Between Amyloid-Β (Aβ) And The Nlrp3 Inflammasome, Cristina Sinobas Pereira

Dissertations

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. While Amyloid-β (Aβ) aggregation is a defining pathological feature, increasing evidence highlights chronic neuroinflammation as a critical contributor to disease progression. Soluble Aβ assemblies can act as damage associated molecular patterns (DAMPs) including activation of the NLRP3 inflammasome, which links amyloid pathology to sustained inflammatory responses in the brain (Heneka et al., 2015; Nakanishi et al., 2018). However, the molecular mechanisms by which specific Aβ conformations influence inflammasome assembly remain incompletely understood.This study aimed to investigate whether distinct aggregation states of amyloid β42 (Aβ42) are …

Disrupted Nuclear Function And Nucleocytoplasmic Transport In Parkinson’S Disease, Ichiro M. Matoba

The Cardinal Edge

No abstract provided.

Design And Advancement Of Analytical Frameworks For In Vivo Single-Photon Calcium Imaging To Characterize Temporal- And Treatment-Dependent Neural Adaptations To Opioid Exposure And Withdrawal In The Medial Prefrontal Cortex, Alexia R. Alsum Dr.

Theses and Dissertations--Pharmacy

Despite the availability of several approved medications for opioid use disorder (OUD), it remains a significant public health concern characterized by persistent neurobiological adaptations that drive relapse and impede successful recovery. The medial prefrontal cortex (mPFC), a region critical for executive control and decision-making, undergoes pronounced functional changes during chronic opioid exposure and withdrawal, yet the cellular mechanisms underlying these adaptations remain poorly understood. This dissertation aims to investigate longitudinal alterations in mPFC neural activity across opioid exposure and withdrawal using in vivo single-photon calcium imaging and newly developed computational frameworks.

Following standard preprocessing to extract and normalize calcium traces, …

Disrupted Circadian Rhythms Affect Hallmark Pathologies In Alzheimer’S Disease-Related Mouse Models, Valeria Buzinova

Theses and Dissertations--Molecular and Cellular Biochemistry

Alzheimer’s Disease (AD) is a complex neurodegenerative disease with two hallmark pathologies: extracellular amyloid-b (Ab) and intracellular neurofibrillary tangles (NFTs). Ab is proteolytically processed from amyloid precursor protein (APP) by b-secretase and g-secretase as a monomeric peptide prone to aggregation. Eventually, the aggregate-prone monomers will form dense plaques that are difficult to break down and remove. These plaques begin to deposit into the cortex decades prior to the formation of NFTs and the onset of cognitive decline. NFTs are comprised of hyper-phosphorylated tau. Tau is a protein that serves to promote and stabilize the formation of microtubules. The formation of …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

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 …

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 …

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 …

Apolipoprotein E4, Tauopathy, And Brain Injury: Molecular Insights Into Alzheimer's Disease Pathology, Nashanthea J. Roland

Theses & Dissertations

Alzheimer’s disease (AD) is the world’s leading cause of dementia, characterized by progressive atrophy of the hippocampal and cortical brain regions, synapse damage and loss, and a buildup of senile plaques and neurofibrillary tangles composed of β-amyloid peptides and hyperphosphorylated tau, respectively. While age is the most significant risk factor for developing AD, apolipoprotein E4 (APOE4) is the strongest genetic risk factor for AD. Although it is known that APOE4 influences tau pathology, the molecular mechanisms by which APOE4 drives AD pathogenesis and progression remain unclear. In addition to intrinsic contributions to AD, there are many extrinsic factors that can …

Assessing The Behavioral Impact Of Pyridostigmine Bromide In Rats, Noah A. Martin

Honors Theses

Pyridostigmine bromide (PB) is an organophosphate (OP) nerve agent prophylactic used to protect warfighters against chemical warfare agents. OPs inhibit the neural enzyme acetylcholinesterase (AChE) in the brain. This leads to the buildup of acetylcholine, causing respiratory failure, seizures, and death. PB functions by inhibiting ~30% of peripheral AChE temporarily, protecting the enzymes so that the body is able to restore sufficient cholinergic function post-exposure. PB does not cross the blood-brain barrier, though it may still indirectly affect toxicity in the brain due to repeated AChE inhibition throughout treatment, or by inhibition of non-target ChE’s in the blood. The aim …

Neuronal Cftr: A Study Of Subcellular Localization And Interactions With Implications For A Role In Synaptic Transmission, Brandon J. Leviskas

LSU Doctoral Dissertations

Protein-protein interactions vary among cell types and the localization of these interactions help to define protein function. The function of cystic fibrosis transmembrane conductance regulator (CFTR) is well established in the context of epithelial tissue due to the debilitating effects of its mutations that cause the disease cystic fibrosis. While in neurons a role has been established in our lab for CFTR in the regulation of cytosolic Cl- in retinal amacrine cells (ACs). This research sets out to learn if CFTR has a synaptic role. Exploring this potential role, localization of CFTR was examined using fluorescent and immunogold labeled transmission …

In-Silico Modeling And Characterization Of Kcc2 Protein Interaction With A Small Molecule Direct Agonist Identifies Potential Binding Sites For Modulating Behaviors Associated With Substances Of Abuse, William Hai Dang Ho, Alfred Amendolara, Kenyon Mitchell, Jaden Miner, Ruth Northcott, Braxton Bingham, Andrew J. Payne

Annual Research Symposium

Purpose

KCC2 is a potassium-chloride cotransporter that plays a critical role in neuronal function by regulating GABAergic signaling via chloride gradients. Maintaining this concentration gradient is crucial for balancing excitation and inhibition in the brain. While KCC2 dysregulation has been implicated in epilepsy and seizures, recent studies suggest that KCC2 inhibition results in phenotypes mirroring those seen in chronic opioid dependence. As such, increasing evidence support KCC2 being a potential therapeutic target for modulating behaviors associated with substances of abuse. Currently, only a few direct small molecule agonists against KCC2 have been reported, and no definitive active site on the …

Use Of Synthetic Water-Soluble Kcc2 To Modulate Chloride Homeostasis In Cultured Dopamine-Neuron-Like Cells, Mason Terry, Andrew Payne, Dario Mizrachi

Annual Research Symposium

No abstract provided.

Technological Development Of In-Cell Nmr: Microfluidic, Metabolomic, And Fluxomic Approaches, Nicholas Sciolino

Electronic Theses & Dissertations (2024 - present)

In the fields of structural biology, metabolomics, and fluxomics, there is a driving, technique-based concern when it comes to high-resolution spectrometry and its marriage to biological and physiological relevance. Sample preparation often involves cellular perturbation, lysate separation schemes, combinations with non-biological reagents, and timeline slack. Conceptually, the farther we get from the cell, the greater the potential disparity between what exists in vivo and our in vitro manipulations. This is particularly true when seeking to collect data on transfected targets of interest, and on sensitive metabolic equilibria that occur on the order of minutes. The question remains: if we are …

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 …

Inductions Of Long-Term Potentiation With Biomimetic Electromagnetic Fields In Primary Neurons, Cooper E. Kansala

Theses and Dissertations (Comprehensive)

Endogenous brain rhythms guide neural communication and plasticity, raising the question of whether weak, temporally structured electromagnetic fields (EMFs) that mimic these rhythms can modulate neuronal activity in a targeted, biomimetic manner. This thesis investigates whether patterned EMFs designed to reflect the temporal structure of hippocampal long-term potentiation (LTP) are more effective at inducing neural plasticity than conventional sinusoidal fields or no stimulation at all. Cortical neurons cultured from postnatal rats were exposed to patterned EMFs for 30 minutes and assessed across three distinct experimental domains. In Chapter 2, microelectrode array (MEA) recordings revealed that the LTP-patterned field significantly increased …

Regulation And Function Of Mec-2 Alternative Splicing In Single Cells, Canyon Calovich-Benne

Biological Sciences Theses and Dissertations

One mechanism for generating diversity at the single cell level is selective expression of a unique set of transcription factors (TFs) and RNA binding proteins (RBPs). These regulatory factors contribute to functions of cells by controlling cell fate, turning genes on and off, and processing of transcripts either co- or post-transcriptionally. Many genes, especially neuronal genes, have multiple different splicing events, promoters, and/or polyadenylation sites. Post-transcriptional coordination is in the infancy of being studied and the functional consequences of this coupling at the single cell level has yet to be explored. Here we show, mec-2 coordination of alternative transcription start …

Investigating Tumor Growth And Regulation In Supratentorial Ependymomas; The Impact Of Dlk1 And Egr1 Knockout, Om Sinojia

Honors Scholar Theses

Ependymomas (EPNs) are primary brain tumors that often arise from radial glial cells lining the ventricular system. Supratentorial ependymomas (ST-EPNs) are particularly aggressive, and understanding the molecular factors driving their growth is critical for developing targeted therapies. This study investigates the roles of DLK1 and EGR1, key regulators in cellular differentiation and tumorigenesis, in the development of ST-EPNs. We utilized genetically engineered mouse models to induce postnatal knockouts of DLK1 and EGR1 and evaluated tumor growth using histological and imaging techniques. Tumor area was quantified across multiple brain sections from both male and female mice. DLK1 knockout brains exhibited consistent …

Targeted Long-Read Sequencing To Quantify Methylation Of The C9orf72 Repeat Expansion, Evan Udine, Nicole Finch, Mariely Dejesus-Hernandez, Jazmyne L. Jackson, Matthew C. Baker, Siva Arumugam Saravanaperumal, Eric Wieben, Mark T. W. Ebbert, Jaimin Shah, Leonard Petrucelli, Rosa Rademakers, Björn Oskarsson, Marka Van Blitterswijk

Neurology Faculty Publications

Background The gene C9orf72 harbors a non-coding hexanucleotide repeat expansion known to cause amyotrophic lateral sclerosis and frontotemporal dementia. While previous studies have estimated the length of this repeat expansion in multiple tissues, technological limitations have impeded researchers from exploring additional features, such as methylation levels.

Methods We aimed to characterize C9orf72 repeat expansions using a targeted, amplification-free long-read sequencing method. Our primary goal was to determine the presence and subsequent quantification of observed methylation in the C9orf72 repeat expansion. In addition, we measured the repeat length and purity of the expansion. To do this, we sequenced DNA extracted from …

Characterization Of Stealth Liposome-Based Nanoparticles Encapsulating Acat1/Soat1 Inhibitor F26: Potential Therapeutics For Niemann-Pick Type C And Other Neurodegenerative Diseases., Junghoon Lee

Dartmouth College Ph.D Dissertations

Cholesterol dysregulation is implicated in neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD) and Niemann-Pick type C disease (NPCD). This study focused on evaluating the potent ACAT1 inhibitor, F26, as a therapeutic strategy for NPCD. F26 demonstrated superior ACAT1 inhibition and efficacy compared to the previously studied inhibitor, F12511, both in vitro and in vivo. Notably, F26 exhibited enhanced pharmacokinetic properties, including prolonged duration of action and better brain retention, making it a more promising candidate for treating neurodegenerative diseases.

F26 was encapsulated in a liposome-based nanoparticle system, DSPE-PEG2000 with phosphatidylcholine (PC), for enhancing its …

Voltage Set Points For Sodium Channel Inactivation: Intrinsic And Modulatory Mechanisms, Akshay Sharma

Dissertations, Theses, and Capstone Projects

During an action potential, voltage-gated sodium channels (VGSC) control sodium ion flow into the cytoplasm of cells by using membrane voltage to alter channel conformation. These membrane proteins exhibit three main functional conformations: closed, open, and fast-inactivated, with transitions between these states dependent on membrane voltage and kinetics. The channels open within 1 millisecond and swiftly transition from open to fast-inactivated within 1-2 milliseconds following membrane depolarization. Subsequent membrane repolarization resets the channels to the closed state. Notably, even at mildly depolarized potentials that preclude channel opening, VGSCs can undergo transitions between the closed and inactivated states, known as closed-state …

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

The Effect Of Novel Microtubule Modulators On Experimental Lewy Body Disease, Anuj S. Jamenis

Electronic Theses and Dissertations

In Lewy body disorders, α-synuclein aggregates are believed to destabilize the microtubular framework. However, microtubules are a challenging therapeutic target, as excessive rigidity or flexibility afforded by microtubule modulators may be neurotoxic. Thus, the objective of the present study was to evaluate dual-acting microtubule- stabilizing/destabilizing agents in cellular and animal models of early-stage Lewy body disease.

In Aim 1 we tested the dual-acting tricylic pyrimido[4,5-b]indole analogs AG161-47 and AG161-41 in an in vitro preformed fibril induced model of Lewy body disease. We found that both compounds reduced preformed fibril-seeded α-synucleinopathy without toxicity in primary hippocampal cultures. AG161-47 subtly impacted microtubule …

Unveiling The Nexus Of Cellular Quality Control: Exploring The Interplay Between Ribosome-Associated Protein Quality Control And Mitochondrial Quality Control Pathways, Foozhan Tahmasebinia

Biological Sciences Theses and Dissertations

In eukaryotic cells, the intricate interplay between cellular quality control mechanisms is crucial for maintaining homeostasis and safeguarding the integrity of vital processes, spanning from macromolecule synthesis to the renewal of entire cellular organelles.

Disruption of these networks can lead to severe diseases such as metabolic disorders, underscoring the interconnected nature and feedback control mechanisms inherent in biological systems, including cellular quality control systems. This interconnectedness extends to the intricate communication between organelles, enabling coordinated functioning and adaptation to changing cellular conditions, particularly in response to stressors.

While the exact mechanisms governing these communications within cellular quality control systems remain …

In Silico Identification Of Small Molecule Agonist Binding Sites On Kcc2, Kenyon Mitchell, Alfred Amendolara, Ruth Hunter, Jaden Miner, Andrew Payne

Annual Research Symposium

Purpose: Potassium-Chloride Cotransporter 2 (KCC2) is a neuronal membrane protein specific to the central nervous system. It is responsible for removing Cl- ions from the intracellular space, maintaining a normal Cl- gradient essential for proper function at inhibitory synapses. Dysregulation causes an upward shift in the Cl- reversal potential resulting in a hyperexcitable state of the postsynaptic neuron. Existing literature indicates that KCC2 may be involved in the addiction pathway of a variety of drugs of abuse, including opioids and alcohol. This makes KCC2 an attractive potential drug target when treating substance use disorders. A novel direct KCC2 agonist, VU0500469, …

Calcium And Proteasomal Regulation Of Er-To-Golgi Protein Transport In Neurons, Samuel A. Galindo

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Regulatory mechanisms of protein trafficking from the endoplasmic reticulum (ER) are critical to understand since neurodegenerative diseases involve defects in this process leading to chronic ER stress and cell death. This study aimed to better understand the calcium regulatory mechanisms of ER-to-Golgi trafficking in hybrid neuroglioblastoma cells (NG108). Specifically, we asked whether proteasomal degradation of transport machinery was involved in the previously demonstrated upregulation of ER-to-Golgi transport evoked by calcium signaling. Based upon previous literature, we believe that the calcium induced increase in transport is due to the activation of the calcium sensitive regulatory protein apoptosis linked gene 2 (ALG-2) …