Neuroscience and Neurobiology Commons^™

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 …

The Role Of Excitatory Neuromodulation In Managing Variability Of Neural System Output, Omar Itani

Dissertations

Neural systems can generate consistent outputs across a population despite substantial variability in the underlying components of individuals. This dissertation aims to identify mechanisms through which neuromodulation influences the relationship between parametric and output variability in neural systems. Through a combination of theoretical analysis, computational modeling, and data-driven approaches, the research addresses how excitatory neuromodulation can shape population-level activity variability and identifies key patterns that govern the production of consistent neural population output despite underlying parameter variability.

The theoretical foundation is established by considering how excitatory neuromodulation affects population variability in simplified neuronal models. Two fundamental patterns of variability reduction …

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 …

Comparative Efficacy Of Combined Versus Singular Auditory Alpha-Theta Brainwave Entrainment And Hypnotherapy Modalities In Chronic Pain Management, Jennifer Nicole Leavitt

Doctoral Dissertations and Projects

This experimental quantitative research, a randomized controlled trial, evaluated combined efficacy of auditory alpha-theta brainwave entrainment (BWE) and hypnotherapy in chronic pain management versus each modality alone. Chronic pain is a serious clinical challenge that may benefit from novel, nonpharmacological interventions. Previous studies have demonstrated benefits of both BWE and hypnotherapy for pain; but research on combined effects was not identified. This study hypothesized that a synergistic approach would offer superior pain relief compared to singular modalities. The study utilized a randomized controlled trial design with a sample size of 38 participants, initially, aged 25 to 65 years old, recruited …

The Role Of Cephalic Mechanosensory Bristles In Flight Initiation Of The Oleander Hawkmoth, Daphnis Nerii, Maitri Manjunath

Theses and Dissertations

During flight, insects sense air movement past their bodies via sensory bristles distributed all over their body. These bristles provide mechanosensory feedback to their nervous system, thereby modulating wing motion to cope with ambient wind conditions. In many insect systems including locusts, moths, etc., flight can be rapidly initiated by stimulating a set of bristles called cephalic bristles on their head. Rapid initiation of flight requires diverse, distributed flight-related reflexes to be simultaneously activated.

Thus, we hypothesized that cephalic bristles directly and simultaneously trigger diverse flight-related reflexes. We tested this hypothesis using the Oleander hawkmoth, Daphnis nerii, as our study …

Administering A Mitophagy Inducing Compound (Mic) To Suppress Neuropathology In A Mouse Model Of Alzheimer’S Disease, Zachary Mayeri

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Despite FDA-approved amyloid-beta (Aβ) therapies in Alzheimer’s disease (AD), Tau pathology remains untreated and is closely linked to cognitive decline. Mitophagy, the process of mitochondrial degradation, is vital for maintaining neuronal health, and its dysregulation is implicated in AD. Recently, our lab identified a mitophagy inducing compound (MIC) that extends the lifespan of C. elegans. We hypothesized that MIC would significantly mitigate neuropathology in an AD mouse model. In this study, aged 3x-Tg AD mice were fed an MIC-containing diet, and immunohistochemistry (IHC) was performed on hippocampal tissue to visualize Aβ and phospho-Tau (pTau) lesions. While MIC had little …

Honey Bee & Reward Loss: A Deep Dive Into The Alarm Pheromone, Citlalli Guadarrama

Masters Theses (Archived)

No abstract provided.

The Manifestation Of Synesthesia In The Deaf, Hard-Of-Hearing, And Sign Language User Population, Elizabeth Droubi

Undergraduate University Honors Capstones

This capstone project investigated the prevalence and manifestation of synesthesia—a perceptual condition where stimulation in one sensory pathway triggers automatic, involuntary experiences in another—within d/Deaf, hard-of-hearing (DHH), and sign language user populations. Despite an estimated prevalence of over 4% in the general population and findings that many synesthetic experiences are language-based, little is known about how synesthesia presents across different language modalities, including signed languages. This project explored the phenomenon in two phases: an initial online survey assessing the prevalence and characteristics of synesthesia among DHH and signing individuals and follow-up interviews with self-reported synesthetes along with a test-retest procedure …

Capturing The Representational Dynamics Of Face Perception In Deep Recurrent Neural Networks, Hossein Adeli, Chase W. King, Nikolaus Kriegeskorte

MODVIS Workshop

We investigate the representational dynamics of recurrent convolutional neural networks (RCNNs) in order to understand the time-course of visual recognition. We explore a family of models with bottom-up and lateral connections that were optimized for face-identification and object-recognition tasks. Using representational similarity analysis (RSA), we observed that only models that were trained for face identification showed a late-emerging prominent distinction of identities as seen in the monkey face patch AM. Early model responses strongly separated the objects from the faces. These findings suggest that the dynamics of face recognition that emerges in a hierarchical recurrent neural network prioritizes category-level recognition …

Attention Improves Classification Performance Of Locations In Ventral And Dorsal Visual Pathways, Jinho Lee, Sung-Mu Lee, Ishita Agarwal, Anne Sereno

MODVIS Workshop

Visual processing is divided into a ventral and dorsal pathway, thought to be important for object recognition and spatial cognition, respectively. Yet both streams encode shape and spatial information, and both are modulated by attention and task demands. This study compared how attention influences fMRI bold responses in a ventral region (fusiform gyrus, FG) and dorsal region (superior parietal gyrus, SPG). Specifically, using multivariate pattern analysis within each region, we examined whether attention modulated spatial location classification performance. During fMRI scans, participants performed one of 3 possible tasks: a 1-back task under attend-to-shape (detect a shape repetition); a 1-back task …

Assessing The Effects Of Streptozotocin-Induced Hyperglycemia On Amyloid Beta Accumulation And Cognitive Behavior In A Mouse Model Of Alzheimer’S Disease-Related Pathology, Andrew Adonay Ortiz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s disease (AD) is an irreversible and devastating neurodegenerative disease characterized by progressive synaptic, dendritic, glial, and neuronal loss, collectively leading to impairments in learning, memory, and deterioration of cognitive and behavioral functions. AD is the most common form of dementia accounting for 60-80% of all cases. AD affects approximately 7 million Americans and is the 6th leading cause of death in the US. Furthermore, by 2050, the US is projected to spend over $1.1 trillion on AD-related treatments. Pathological hallmarks of AD include beta-amyloid (Aβ) plaques, intracellular neurofibrillary tangles (NFTs), and chronic neuroinflammation, which can promote and exacerbate both …

Peripheral Neuroimmune Mechanisms Of Chronic Back Pain, Aleyah Esther Goins

Biomedical Sciences ETDs

Chronic back pain (CBP) affects 1 in 10 people worldwide, reducing mobility, productivity, and quality of life. Despite its prevalence, non-addictive treatments remain limited due to an incomplete understanding of chronic pain mechanisms. This dissertation examines peripheral neuroimmune interactions in CBP using a urokinase-type plasminogen activator (uPA)-induced mouse model (uPA-CBP). uPA, a pro-inflammatory serine protease, was injected into the L2/L3 lumbar spinous ligament, inducing prolonged mechanical and cold hypersensitivity. Flow cytometry of dorsal root ganglia (DRG) showed increased CD45+CD11b+ myeloid cells in males and CD45+CD3+CD4+ lymphocytes in females. DRG neurons from male uPA-CBP mice exhibited heightened action potential firing. Pharmacological …

Comparing Apples To Oranges From Photoreceptors To Inferotemporal Cortex, Qasim Zaidi, Xu Yi, Akihito Maruya, Bevil Conway

MODVIS Workshop

No abstract provided.

Perceptograms And Cortical Models For Amblyopic Form Distortions, Akihito Maruya, Farzaneh Olianezhad, Jingyun Wang, Jose-Manuel Alonso, Qasim Zaidi

MODVIS Workshop

No abstract provided.

Influence Of Task On The Geometry Of A Perceptual Space, Jonathan D. Victor, Mary M. Conte

MODVIS Workshop

Perceptual spaces are representations of a sensory or cognitive domain in which the domain’s elements correspond to points, and distances between these points are perceptual differences. Proximity relationships within a perceptual space can support a variety of functions, including discrimination, grouping, learning, and generalization. These diverse functions may use the features of the domain in different ways, resulting in task-dependent influences on the geometry of the space.

To identify and characterize these influences, we focused on a domain of visual textures. These textures varied across many dimensions, including mean luminance and low- and high-order spatial correlations, which formed the axes …

Using Neural Networks To Better Understand Static And Dynamic Components Of Facial Expression Recognition, Yi-Fan Li, Anne Bibiana Sereno

MODVIS Workshop

Facial expressions are crucial social information for human communication. In the real world, facial expressions are dynamic; however, much of existing research in facial expressions relies on static stimuli. This static approach may limit the ecological validity of our understanding of the emotional information on faces. Our study aims to investigate the dynamic and static information contained in different emotional categories of facial expressions (e.g., happy, sad). Four convolutional neural networks are introduced as models to be trained with a large-scale dynamic facial expression dataset (short videoclips of 16 frames of 7 different emotional categories) in four different ways: ordered …

Modeling Effects Of Edge Classification And Perceptual Organization On The Appearance Of Disk/Annulus Stimuli, Michael E. Rudd

MODVIS Workshop

In classical theories of sensory psychophysics, appearance matches conducted with simple stimuli consisting of disks surrounded by annuli were posited to probe low-level contrast mechanisms in the visual pathways that computed the approximate luminance ratio between the disk and annulus for the purpose of achieving lightness constancy (Wallach, 1948). Subsequent models have explained such matches on the basis of neural edge integration (Shapley & Reid, 1985; Rudd & Zemach, 2004). Here, I demonstrate that appearances matches made in the disk/annulus paradigm are influenced by at least two types of top-down effects involving edge classification and perceptual organization. I present a …

Fixational Eye Movements Shake Up The Stationary View On Pattern Vision, Lynn Schmittwilken, Marianne Maertens

MODVIS Workshop

No abstract provided.

A Computational Perspective On Segregated Processing And The Privileged Role Of Space In Binding, Anne Sereno, Zhixian Han, Elizabeth M. Frazier

MODVIS Workshop

No abstract provided.