Neuroscience and Neurobiology Commons^™

The Role Of The Avian Medial Hippocampal Formation In High-Similarity Spatial Discrimination, Alexandre Lebel

Theses and Dissertations (Comprehensive)

Similar stimuli can create spatial-perceptual challenges, thus leading to errors in recall. To combat this interference, organisms rely on processes within the hippocampal formation (HF) that support the discrimination of highly similar memories. In mammals, memory interference is thought to be reduced by decreasing the correlation between traces of similar events; a process termed pattern separation, often by the dentate gyrus. The extent to which birds, which have granule cells (GCs) but lack a dentate gyrus, utilize HF-dependent mechanisms to mitigate memory retrieval errors remains unclear. This study investigates the role of the triangular region and area V (proposed homologs …

Endogenous Light In The Brain: Investigating Sources, Propagation, And State-Dependent Emission, Emre Cicek

Theses and Dissertations (Comprehensive)

Ultraweak photon emission (UPE), and by extension light, has long been thought to be a modality of communication in nature. Prior studies have already identified that UPE can depend on cell type and can be used to discern between malignant and benign cells. However, besides theoretical models, not much effort has been made to identify possible biological structures that would allow for light to be used as a method of communication in the human body. According to the framework set by Shannon’s Information Theory, for communication to be possible at minimum a transmitter, a transmission channel, and a receiver are …

Artificial Sentience: From Computational Functionalism To Behaviourism?, Wanja Wiese

Animal Sentience

I critically examine Jonathan Birch’s account of how brain emulations might create artificial sentience candidates, arguing that his account risks collapsing into a behaviourist account, unless the specific computational processes realised by such emulations are carefully considered. Drawing on examples from computational neuroscience, I show that similar behaviours can arise from vastly different computational processes, thereby undermining the suggestion to focus on behaviourial profiles to determine whether a brain emulation of a sentience candidate is itself a sentience candidate.

Obsessive-Compulsive Subtraits And Self-Agency, Jacob Nelson, Cody Barton, Carissa Phillipi Phd

Undergraduate Research Symposium

Obsessive-Compulsive Disorder (OCD) is categorized by persistent, unwanted thoughts, called obsessions. and repetitive behaviors, called compulsions. The Obsessive-Compulsive Inventory-Revised (OCI-R) is a valid measure of OCD, and breaks the condition into six subtraits: Checking, Hoarding, Obsessing, Ordering, Neutralizing, & Washing. Prior research has suggested that one’s sense of agency, measured through the Sense of Agency Scale (SoAS), is lower in those with higher overall OCI-R scores compared to those with lower scores and controls. Additionally, sub-clinical checking has been negatively correlated with sense of agency, and sub-clinical hoarding and ordering have been positively correlated with sense of agency. However, there …

The Cranial Nerves And Electrical Stimulation, Devin K. P. Adair

Dissertations, Theses, and Capstone Projects

Cranial nerves provide afferent pathways that enable bottom-up modulation of central autonomic and cognitive neural pathways. Because these pathways project to brainstem nuclei such as the nucleus tractus solitarius and engage neuromodulatory systems, including the locus coeruleus, electrical stimulation offers a mechanistically grounded approach to influencing brain function. This thesis tested whether active transcutaneous auricular vagus nerve stimulation (taVNS) produces physiological responses indicative of parasympathetic engagement, defined as decreases in heart rate, increases in heart rate variability, and decreases in respiration relative to a dose-matched earlobe control condition. Using cardiac and respiratory measures as physiological markers, taVNS at the tragus …

Unraveling Hemispheric Specializations In The Mouse Auditory Cortex: From Diseased Model Comparisons To Development, Demetrios Neophytou

Dissertations, Theses, and Capstone Projects

Hemispheric specialization is a fundamental organizing principle of mature auditory cortical function, allowing the left and right Auditory Cortex (ACx) to perform complementary computations on complex sounds. This division of labor is conserved across species, and mice recapitulate key forms of auditory cortical lateralization, providing access to the synaptic and circuit mechanisms that generate it. Disrupted hemispheric organization is also associated with neurodevelopmental disorders characterized by severe communication impairments, including Rett Syndrome (RTT). Despite this, we know little about how lateralized auditory circuits are assembled during development or why they become differentially vulnerable to neurodevelopmental disruption. Here, using a mouse …

The Effects Of Chronic Nicotine Exposure On Dopamine-Mediated Reinforcement Learning And Striatal Neurotransmission, Srishti Bose

Dissertations, Theses, and Capstone Projects

Tobacco is one of the most widely used substances across the United States; tobacco consumption is linked with several diseases and is one of the leading causes of preventable death in the country. Nicotine is the active substrate found in tobacco products, acting as a stimulant, which reinforces continued use. The introduction of tobacco-free options such as e-cigarettes and oral pouches has driven an increase in nicotine exposure across the population, especially in young adults. Acute nicotine use induces neuroadaptations in the mesolimbic dopaminergic system, which mediates reinforcement learning and addiction, that potentiates reward-related neurotransmission. Furthermore, there are clinical studies …

Towards Identifying Fear And Safety Network States Across Sex, Rhonda Kolaric

Dissertations, Theses, and Capstone Projects

Post-traumatic stress disorder (PTSD) is a trauma- and stressor-related disorder with a lifetime prevalence of 5-6% in men, and 10-12% in women (National Center for PTSD). Generalized anxiety disorder (GAD) is a highly prevalent anxiety- and depression-related psychiatric disorder with a lifetime prevalence of 1-2% in men, and 3-4% in women (National Institutes of Health). Both of these disorders disproportionately affect women. A hallmark feature of both disorders is the maladaptive generalization of fear, in which defensive responses extend beyond the original traumatic or threatening stimulus to neutral or unrelated cues. This overgeneralization can become debilitating, disrupting cognitive, emotional, and …

From Insect Cognition To Sentience: Exploring The Edge, Catherine Macri, Martin Giurfa

Animal Sentience

What does The Edge of Sentience tell us about insect sentience and consciousness? In this commentary, we reflect on Jonathan Birch’s framework for defining and scientifically investigating sentience in animals. We discuss the methodological challenges of studying subjective experience in evolutionary distant species, and consider trace conditioning, affective states, and neural architectures as potential windows into consciousness in insects. We argue that uncertainty, whether concerning definitions or methodology, should not prevent experimental investigation; rather it should motivate new approaches and experimental designs for exploring the diversity of conscious experience.

Hemodynamic Characterization Of Cardiac Dysfunction After Traumatic Brain Injury Using A Controlled Cortical Impact Model In Male Rats, Preston So, Amit Iyengar, Noah Weingarten, Mrinal Patel, Jessica Dominic, Andrew Belec, Joyce Ho, Samuel Shin, Pavan Atluri

Division of Cardiology Faculty Papers

Traumatic brain injury (TBI) is associated with cardiovascular dysfunction that worsens clinical outcomes, yet the underlying mechanisms are poorly under stood. Clinical studies are limited by heterogeneity, highlighting the need for con trolled experimental models. Controlled cortical impact (CCI) provides precise control of injury severity, and invasive pressure- volume (PV) loop analysis allows detailed hemodynamic assessment. Adult male Wistar rats underwent sham op eration or mild or severe CCI- induced TBI. PV- loop assessment and transtho racic echocardiography were performed at 8 or 24 h after TBI or sham. Serum epinephrine (EPI) and norepinephrine (NE) were quantified by ELISA. At …

Expression Profiling And Bioinformatic Characterization Of Depalmitoylation-Associated Genes During Sh-Sy5y Neuronal Differentiation, Ayesha Lodhi

Seton Hall University Dissertations and Theses (ETDs)

Palmitoylation is a reversible post-translational modification involving covalent attachment of palmitoyl groups to cysteine residues. Till date, 23 members of this family have been identified in mammals, located in Golgi apparatus and endoplasmic reticulum and nearly 40% of synaptic proteins are estimated undergo palmitoylation. These proteins include vesicle fusion proteins (SNARE), signaling molecules, ion channels and neurotransmitter receptors such as gamma-aminobutyric acidreceptors, kainate receptors and glutamate receptors. While its role in neuronal function has been widely recognized, comparatively little is known about how depalmitoylation-associated enzymes are regulated during neuronal differentiation. The present study aimed to characterize changes in depalmitoylation-associated gene …

Letter From The Professor

Scientific Kenyon: The Neuroscience Edition

No abstract provided.

A Novel Role For The Infralimbic Cortex In Conditioned Fear Responding, Julia R. Mitchell, Samantha Tuberman, Rylin Lubash, Leticia C. N. Takasumi, Emmett Bergeron, Roberto Calitri, Mikaela A. Laine, Maryclare Pikus, Victoria Vance, Leena Ziane, Rebecca M. Shansky

Neuroscience: Faculty Publications

Freezing during Pavlovian fear conditioning is the most commonly used indicator of learned fear in rodents. Although freezing and its neural underpinnings have been widely studied, the field has largely ignored other potential indicators of learned fear. Darting, an escape-like conditioned fear response, occurs more frequently in females and is reliably predicted by a distinct behavioral phenotype: heightened shock response and decreased freezing compared to rodents that do not engage in darting. The experiments in this study sought to expand the field’s understanding of conditioned fear by investigating the neural correlates of conditioned darting, focusing on the infralimbic cortex (IL) …

Polyphenol Diet And Exercise As Neuroprotection From Effects Of Alzheimer's Disease, Michelle Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Healthy non-pharmacological lifestyle factors, such as regular physical exercise and a dietary supplementation, have been shown to significantly improve cognitive outcomes over time compared to a more sedentary lifestyle and poor diet. Furthermore, exercise may serve as a potential protective factor in attenuating the effects associated with cognitive decline that are characteristic of neurodegenerative disorders, such as Alzheimer's disease (AD). Further, evidence indicates that certain diet interventions can also attenuate the effects of neurodegeneration and positively impact longevity. Supplementation of polyphenols, such as ellagic acid (EA), which are abundant in pomegranate juice, may help provide neuroprotective benefits and elicit a …

Validated Crispr/Cas9 Guide Rnas Targeting Neurodevelopmental Genes In The Tunicate Ciona Robusta, Sydney Popsuj, Tenzin Kalsang, Eduardo D. Gigante

Faculty Articles

The tunicate Ciona robusta provides a powerful and simplified model for dissecting the genetic control of developmental and cell biology. With a larval CNS composed of just over 200 neurons and sensory cells, it has also emerged as a model organism for neurobiology and the development of the nervous system. Although CRISPR/ Cas9-mediated mutagenesis is now routinely used in Ciona as an important technique used to interrogate gene function in diverse biological processes, validated single-guide RNAs (sgRNAs) have yet to be validated for several key neural genes. Here, we report the design and experimental validation of 25 novel sgRNAs targeting …

History-Dependent Gain Control In The Paraventricular Thalamus: Neural Substrates Of Stress-Enhanced Fear Learning, Michael Martino

MUSC Theses and Dissertations

Post-traumatic stress disorder (PTSD) is characterized by hyperarousal and heightened reactivity that generalize beyond the original traumatic event, yet the neural mechanisms by which prior stress experience biases future fear learning remain poorly understood. Stress-enhanced fear learning (SEFL) is a well-validated rodent model of this phenomenon, in which a severe stressor produces persistent sensitization of subsequent fear acquisition. This dissertation used a 30-day SEFL paradigm to identify the brain-wide functional signature of stress sensitization and to identify candidate neural substrates.

Whole-brain cFos mapping during acute fear acquisition revealed a predominant pattern of suppressed neural activity in sensitized animals, with limbic …

Modulation Of Electrophysiology And Plaque Aggregation In Huntington’S Disease Patient-Derived Cells By Picosecond Pulsed Electric Fields, Mackenzie A. Tardif-Kunk

Biomedical Sciences Theses & Dissertations

Huntington’s Disease (HD) is a fatal, autosomal dominant neurodegenerative disorder characterized by progressive motor and cognitive decline. Unstable expansion of cytosine-adenine-guanine (CAG) trinucleotide repeats in the huntingtin gene, often exceeding 35–40 repeats, results in an extended polyglutamine (PolyQ) tract in the translated protein. Abnormal folding of the mutant huntingtin (mHTT) protein leads to accumulation and aggregation within the cell, dysregulating various cellular processes through molecular sequestration. While several therapeutic strategies have been proposed, this disease remains incurable with treatments limited to symptom management.

Pulsed electric fields (PEF), primarily in the microsecond and nanosecond ranges, have been studied extensively for the …

Prenatal Acoustic Programming Of The Developing Hypothalamus: A Multi-Omic Analysis Of Heat Call Exposure In Zebra Finch Embryos, Prakrit Subba

All Dissertations

Climate change is intensifying thermal stress on wildlife globally, yet the developmental mechanisms by which embryos use prenatal cues to adjust to predicted environments remain unclear. In Australian zebra finches (Taeniopygia guttata), incubating parents produce distinctive heat call vocalizations at high ambient temperatures, and embryos exposed to these calls during late incubation develop altered growth trajectories, thermoregulatory capacity, and reproductive outcomes, suggesting a form of anticipatory developmental programming triggered by sound alone. To investigate the molecular basis of this response, I initially hypothesized that prenatal heat call exposure would act primarily through hypothalamic neuroendocrine reprogramming, given the central …

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 …

Oxidative Stress Mediated Glutamate Release And Nmda Receptor-Dependent Synaptic Remodeling In Radiation-Induced Cognitive Dysfunction, Thanh Lam

Dissertations and Theses (Open Access)

In children younger than 14 years old, the brain and other parts of the central nervous system are the most common sites for solid tumors. Radiotherapy is an effective treatment for central nervous system (CNS) tumors. However, it often causes a progressive decline in cognitive functions, which is especially devastating for pediatric patients. Although post-mitotic neurons are generally considered resistant to radiation-induced immediate cell death, ionizing radiation causes complex neurochemical and structural changes that damage synaptic integrity. In this study, we examined the molecular cascades following a 10 Gy radiation dose applied to mouse cortical neurons. We found that radiation-induced …