Neuroscience and Neurobiology Commons^™

Beyond The Square Pulse: Waveform Shape, Eeg Correlates, And The Pursuit Of Natural Sensation In Tens, Jason Whitson

Honors Undergraduate Theses

This study investigates the relationship between electrical stimulus characteristics of shape and charge on evoked sensations and electroencephalogram (EEG) data during multi-waveform transcutaneous electrical nerve stimulation (TENS) of the median nerve. Neuromodulation methods have traditionally had little control over the location and quality of their associated evoked sensation (e.g., electric, vibration, touch). This experiment utilized five unique stimulus waveforms during TENS stimulation. EEG data were collected concurrently to provide an introductory objective measure of the neural responses underlying these sensory changes. Eleven participants completed three tasks (thresholding, super-threshold stimulation, two-alternative forced choice) using a two-electrode TENS approach. Stimulus waveforms were …

Advances In Active And Passive Integrated Photonic Devices On Thin-Film Lithium Niobate, Pooja S. Kulkarni

Graduate Studies Theses and Dissertations 2026

Thin-film lithium niobate (TFLN) has emerged as a powerful platform for integrated photonics, combining the exceptional electro-optic, nonlinear, and optical properties of bulk lithium niobate with the scalability and compactness of planar nanophotonic technologies. Building on these principles, advanced device architectures such as adiabatic dichroic filters have demonstrated exceptional spectral performance spanning over two octaves of bandwidth on the TFLN platform. Beyond reciprocal devices, it also offers promising pathways toward integrated nonreciprocal components. By leveraging broadband filtering structures and advanced nonlinear photonic design strategies, compact and monolithic optical isolators can be envisioned without relying on traditional magneto-optic materials. In the …

The Influence Of Limb Dominance On Neural Activation Patterns While Performing Different Motor Control Tasks, Kevin A. Hooks

Graduate Studies Theses and Dissertations 2026

Humans interact with our environment in many ways. One of the most outward-facing aspects of this is limb dominance. The neural underpinnings of limb dominance remain in question today. The objective of this research was to use different methods to analyze neural activation while subjects performed upper extremity motor tasks while recording electroencephalography (EEG). The first experiment used decoding methods to examine whether neural signals collected from the contralateral limb could be used to train a classifier to test on the ipsilateral limb during a reach-to-grasp or reach-to-touch task. It was determined above chance level that within-subject action and direction …

The Effects Of Environmental Complexity On Brain Development And Personality Expression In Western Hognose Snakes, Gokulan Nagabaskaran

Theses and Dissertations (Comprehensive)

There is growing interest in snake cognition, personality, and welfare as more snakes are kept as pets, yet little research has been conducted. The effects of enrichment and environmental factors have been well documented in other taxa, and recent evidence suggests that snakes may benefit in similar ways. This dissertation investigated the impact of environmental and social enrichment on personality expression, personality stability, and brain development. Western hognose snakes (Heterodon nasicus) were used as the model species, as they are a popular choice in the pet trade. This allows the research to be readily translatable to husbandry practices of many …

Adapting To Uncertainty: Effects Of Environmental Instability On Zebrafish Behaviour, Britney Sekulovski

Theses and Dissertations (Comprehensive)

This thesis addresses how animals cope with unpredictability by testing how environmental stability changes the behaviour of zebrafish (Danio rerio) in two complementary experiments. In Experiment 1, fish lived for three months in either a Dynamic environment (water temperature, feeding times, habitat complexity, group size, and membership fluctuated) or a Stable environment (all factors constant). Across seven behavioural assays, measuring individual behavioural differences, collective movement, social memory, and information use, Dynamic condition fish were found to be more sensitive to social cues and more likely to conform to recent social information, independent of the quality of the information …

Eeg Correlates Of Tactile Synchrony, Devon K. R. Gallagher

Theses and Dissertations (Comprehensive)

New research on the tactile system has suggested that cortical representations of body parts are not fixed, as previously thought, and are instead dynamically maintained through constant sensorimotor information and feedback. Within the somatosensory cortex (S1), the capacity for both permanent and temporary changes have been the topic of ongoing research. The current study aimed to corroborate whether 24 hours of a finger adhesion manipulation is sufficient to elicit behavioural and electrophysiological correlates from cortical reorganization of digit representations in S1, using a behavioural paradigm outlined by Kolasinski et al. (2016). Through electroencephalography (EEG) recording during a tactile discrimination task, …

Assessing The Effects Of Theta Transcranial Alternating Current Stimulation During Working Memory Performance On Theta-Gamma Phase Amplitude Coupling In Healthy Adults, Samantha M. Zimmer

UNF Graduate Theses and Dissertations

Transcranial alternating current stimulation (tACS) is an emerging form of noninvasive brain stimulation with substantial effects on behavior and brain function due to its ability to entrain endogenous neural oscillations. Working memory is a cognitive process that involves holding onto information that is no longer present in the environment and manipulating or reorganizing information for immediate use. Theta oscillations are critical for the functionality of the frontoparietal network and are involved in strengthening communication and coordination between frontal and parietal brain regions, especially during working memory processing. TACS applied at the theta frequency, targets theta oscillations, strengthens network communications, and …

Mitochondrial Disorders Should Be Considered As A Differential Diagnosis Of Thiamine Deficiency, Josef Finsterer

HCA Healthcare Journal of Medicine

This letter to the editor addresses limitations to diagnosing thiamine deficiency for multisystem disorders and discusses the potential differential diagnoses that must be considered.

Towards Computational Methods In Medical Data Analysis: From Speech And Text To Imaging, Kristin Qi

Graduate Doctoral Dissertations

Early detection of cognitive decline and efficient medical image analysis remain critical challenges in healthcare. Traditional clinical assessments are infrequent and resource-intensive, while everyday speech data and unlabeled medical images remain largely unexploited. This dissertation develops computational methods integrating machine learning and artificial intelligence across speech, text, and imaging modalities to address challenges in medical data processing. For cognitive monitoring, this work first introduces methods using voice assistant systems to collect longitudinal speech data in home environments, demonstrating that incorporating historical session patterns significantly enhances detection of mild cognitive impairment. Building on this foundation, a framework combining large language model-driven …

Microglial Expression Of Serotonin Receptors Reveals Parallel Regulation Of 5-Ht2b And Bdnf In The Rat Hippocampus, Andrei Turkin, Maria Sidorova, Ekaterina Kurilova, Natalia Alenina, Oksana Tuchina, Friederike Klempin

School of Graduate Studies Faculty Publications

Growing evidence suggests that psychiatric disorders are characterized by a prolonged inflammatory state, which may influence the efficacy of compounds targeting serotonin. Serotonin is a key signaling molecule in neuroplasticity of the adult hippocampus and involved in antidepressant action. Recent in vitro studies indicate the neurotransmitter may also facilitate the response to inflammation and potentially modulate microglial function towards neuroprotection. Using Tph2−/− rats depleted of brain serotonin, we examined microglial expression of various serotonin receptors (5-HTRs) in vivo in both the hippocampus and prefrontal cortex and assessed mRNA levels of cytokines and brain-derived neurotrophic factor (BDNF). We observed age-dependent and …

Micu2 Controls Mitochondrial Calcium Signaling And Migration In Neurons During Development, Elena Berezhnaya, Benjamín Cartes-Saavedra, Raghavendra Singh, Macarena Rodríguez-Prados, Orly Reiner, Fowzan S Alkuraya, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Neurological disorders are linked to mitochondrial dysfunction and calcium overload. Mitochondrial calcium uptake is mediated by the mitochondrial calcium uniporter (mtCU), regulated by MICU1, which can be either homodimerized or heterodimerized with MICU2 or MICU3. Though MICU2 is scarce in the adult brain, MICU2 loss in patients leads to a neurodevelopmental disorder. We hypothesized that MICU2 is required for developmental calcium signaling and neuronal migration. MICU2 is present in the developing mouse brain but disappears by maturation, contrasting with other mtCU subunits that increase. MICU2 loss in mice does not affect cytoplasmic calcium but augments the mitochondrial matrix calcium rise …

An Analysis Of Developmental Changes In Twitch Patterning During Rem Sleep, Claire Wolfer-Jenkins, Taylor Svoboda

The Journal of Purdue Undergraduate Research

No abstract provided.

Effects Of Alcohol Exposure On Recognition Memory And Marble-Burying Tasks In Male And Female Aged Mice, Roma Kamat, Tori Burke

The Journal of Purdue Undergraduate Research

Alcohol consumption in aging humans is a risk factor for cognitive impairment. This experiment assessed the effects of binge-like alcohol drinking in aged mice on memory (using the object recognition memory [ORM] task) and on anxiety-and compulsive-like behavior (using the marble-burying task). Subjects were 8 female and 10 male mice, 14–15 months old, selectively bred for low alcohol preference (LAP). Mice consumed either tap water or a 20% alcohol (v/v) solution in tap water through a drinking in the dark (DID) procedure for 4 consecutive days per week, for 3 consecutive weeks. One and 11 days after DID, mice completed …

Neurofeedback: An Emerging Contender In The Treatment Of Mental And Behavioral Disorders, Makayla Fisher

Student Scholar Symposium

Neurofeedback, an emerging treatment for mental and behavioral disorders, has shown promising results as a holistic alternative to traditional therapy and medication. This treatment was discovered in the 1950s by using an electroencephalography (EEG) device to train people to achieve an alpha state using the reward of a bell sound. Currently, the basis of neurofeedback is using an EEG device that is connected to a video, such as television, to receive positive or negative feedback, corresponding to beneficial or non-beneficial brain activity. After 3-4 weeks of the video dimming in response to non- beneficial brain activity, your brain starts to …

Examining The Relationship Between Gambling Advertising & Gambling Behavior, Ilkim Green, Eric Wickenhauser, Hannah White Ph.D

Undergraduate Research Symposium

Gambling advertising has become increasingly prevalent across various media platforms such as TV, social media, real-life advertising, etc. With advertisements designed to influence attitudes, intentions, and behaviors of potential and existing consumers, this review aims to compile existing research to examine the measurable effects of gambling advertising. Studies indicate that young people and problem gamblers are especially vulnerable to these advertisements, which normalize gambling and contribute to increases in gambling behavior. This effect on behavior is dose-dependent; increased exposure to advertising is associated with greater gambling engagement. While responsible gambling messages are often included in advertisements, they remain largely ineffective …

Dual-Task Exercise Protects Healthy Older Adults Against In-Creased Risk For Dementia: A Controlled Trial, Helen Tatiane Santos Pontes, João Bento-Torres, Naina Yuki Vieira Jardim, Victor Oliveira Da Costa, Josilayne Patricia Ramos Carvalho, Cristovam Wanderley Picanço-Diniz, Natáli Valim Oliver Bento-Torres

Baltic Journal of Health and Physical Activity

Background: Functionality in aging is closely linked to the ability to divide attention during multitasking activities, which are essential for activities of daily life. However, coordination between motor and cognitive simultaneous tasks decreases with age, impairing functional ability and restricting older adults' participation and healthy aging. This study aimed to assess the effects of a multimodal dual-task exercise intervention on motor and cognitive dual-task costs and its potential to mitigate age-related declines in healthy older adults. Materials and Methods: A controlled trial was conducted with community-dwelling older adults assigned to either the Dual-Task Exercise group, which participated in a 24-session …

Investigation Of Mono-Allelic Rack1 Deletion Effects On Cell Growth And Pkc Mrna Expression, Ashen Quiambao

Seton Hall University Dissertations and Theses (ETDs)

The µ-opioid receptor is a primary target of clinically used opioids, and RACK1 regulates its transcription by physically interacting with MOR transcription regulator PCBP1 in the cytosol to prevent its nucleus translocation. Two mono-allelic RACK1 knockout cell lines named RACKA and RACKB were generated by the CRISPR-Cas9 technique using WT NMB neuroblastoma cells. As RACK1 also contains a PKC-binding domain, this study aims to evaluate the impacts of mono-allelic deletion on cell growth rates and PKC isoform expression. Although a slight decreased tendency of growth rate in RACKA and RACKB cells was observed when compared to that of WT NMB …

Acute And Chronic Effects Of Neuroinflammation On Hippocampus And Anterior Cingulate Cortex Network Dynamics, Lauren A. Crew

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neuroinflammation has emerged as a critical modulator of cognitive function and neural circuit dynamics, yet the distinct contributions of acute and chronic neuroinflammation to brain function remain poorly defined. This dissertation examines how inflammation independently alters large-scale neural activity and behavior, focusing on interactions between the hippocampus (HPC) and anterior cingulate cortex (ACC), regions essential for memory and executive processes. Using in vivo electrophysiological techniques in a rodent model, this study compares the effects of short-term (acute) and prolonged (chronic) neuroinflammatory states, induced via Poly I:C, on neural oscillations, regional coherence, and spatial coding. Findings reveal that even transient inflammation …

Neurobehavioral Mechanisms Of Psychotic-Like Experiences And Cannabis Use, Ethan Campbell

Psychology ETDs

As cannabis use has increased steadily over the past decade, there is critical need to evaluate early cannabis use as a potential risk factor for the development of psychosis. Neurobehavioral mechanisms underlying novelty salience could clarify how cannabis exposure may influence subclinical psychotic-like experiences (PLEs). The present study leveraged dynamic functional connectivity and task-fMRI to assess the role of novelty processing in cannabis use and PLEs. A group of brain regions dynamically tied to the salience network while viewing short films were found to increase their activation as a function of stimulus novelty during a novelty bandit task. PLEs were …

Stress During Adolescence: A Characterization Of Anxiety-Like Behavior, And The Mrna Expression Of Neuroimmune Factors, Clock And Stress Genes In Corticolimbic Areas., Annette Fernandez Oropeza, Annette K. Fernandez Oropeza

Biomedical Sciences ETDs

Adolescence represents a critical window of frontal cortex (FC) maturation and corticolimbic circuit refinement that supports stress and emotion regulation. Disruption of these processes by early-life insults such as prenatal alcohol exposure (PAE) or adolescent stress increases vulnerability to anxiety and mood disorders, in part through circadian–immune dysregulation. The circadian transcription factor Bmal1 and the proinflammatory cytokine tumor necrosis factor-alpha (TNFα) have emerged as key regulators of neuroimmune signaling and synaptic communication, yet their interactions across developmental risk contexts remain poorly understood. This dissertation examined the effects of mild adolescent isolation stress, with and without PAE, on anxiety-like behaviors and …

The Need To Incorporate Polysubstance Use In Neuropsychopharmacology Research: Biological Lessons And New Opportunities, Max E. Joffe, Susan M. Ferguson, Nick W. Gilpin, Melissa A. Herman, Lori A. Knackstedt, Patrick A. Randall, Abigail G. Schindler, Mary M. Torregrossa, Jennifer A. Rinker

School of Medicine Faculty Publications

Critical evaluation and refinement of animal models is essential for neuroscientists to understand complex physiological and pathological processes related to psychiatric diseases. In general, preclinical studies modeling drug dependence and problematic substance use have been limited to the administration of a single substance; however, there is a growing appreciation that this approach has failed to capture the complexities of humans and has stifled translational efforts. Polysubstance use represents the overwhelmingly common patterns of alcohol and drug use in humans. For example, epidemiological studies generally determine that between 70–95 % of individuals with alcohol use disorder use tobacco daily, and upwards …

A Pilot Study Of Life Model Informed Therapy And Its Efficacy For Reducing Anxiety And Increasing Joy In Adults, William R. Mouer

Doctoral Dissertations and Projects

This pilot study researched Life Model Informed Therapy (LMIT), a modality developed into a six-week treatment targeted to decrease anxiety and increase joy in adults that self-reported as having anxiety. Fourteen participants were recruited by Facebook ads in the Charlotte, North Carolina area. Outcome data were collected using the State Joy Scale (SJS) and Beck Anxiety Inventory (BAI). Participants received the same LMIT treatment for six consecutive, weekly, one-hour sessions. Participants self-reported on their joy and anxiety levels at three periods of time, including a pre-treatment, post-treatment and one month after-treatment test. Two one-way RM-ANOVA tests were conducted. Results of …

Effects Of Ghost Energy Drink On Muscle Strength, Psychomotor Vigilance, And Mood., Jason M. Curtis, Jose J. Rojas, Flavia F. Pereira, Cassandra Evans, Elizabeth Espocito, Alyana Andal Andal, Gavin Poulshock, Hena Thakkar, Taila De Castro, Alexandra Jimenez, Antonio Cristanti, Antonella V. Schwarz, Juan Carlos Santana, Jose Antonio

Journal for Sports Neuroscience

Abstract

Background: This study aimed to evaluate the effects of a commercially available energy drink (Ghost®) compared to a caffeine-matched control on measures of mental and physical performance.

Methods: In a randomized, double-blind design, 62 participants were assigned to receive either the energy drink (Ghost®) or a caffeine-matched control (200 mg caffeine). Assessments were conducted at baseline and approximately 45 minutes post-ingestion, including the Psychomotor Vigilance Test (PVT), CNS Tap Test, handgrip strength, and the Profile of Mood States (POMS).

Results: Participant demographics are presented in Table 1. No significant between-group differences were observed for any performance measures. Both groups …

Generating Predictive Gene Expression Signatures For Alzheimer's Disease Using Postmortem Brain Tissue, Ashley Duche

Pharmaceutical Sciences (PhD) Dissertations

Background: Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-beta (Aβ) plaques and tau protein aggregates. These pathological features develop in specific brain regions, but why some areas are more vulnerable to early AD-related changes remains unclear. To address this, predictive gene expression signatures were developed to explore the molecular mechanisms underlying regional susceptibility to AD pathology.

Methods: This was performed using postmortem brain (PMB) tissue from participants in the Religious Orders Study and Memory and Aging Project (ROSMAP), Mayo Clinic, and Mount Sinai Brain Bank (MSBB) to generate gene expression signatures from six brain …

Gpu-Based Electromagnetic Microwave Tomography For Brain Imaging And Stroke Detection, Pablo Sotelo Torres

Open Access Theses & Dissertations

Each year, an estimated 795,000 people in the U.S. suffer a stroke, with approximately 610,000 being first-time cases. Of these, 87% are ischemic strokes, while the remaining 13% are hemorrhagic. Current imaging methods, such as Computed Tomography (CT), Positron Emission Tomography (PET), and Magnetic Resonance Imaging (MRI), provide useful information into brain tissue properties; while each technique has its advantages, they remain expensive, non-portable, and often too slow for emergency bedside or in-ambulance use. Electromagnetic Microwave Tomography (EMT) offers a promising alternative: an affordable, portable, rapid, and safe method for stroke detection. By contrasting dielectric properties between healthy and affected …

Modeling And Analysis Of Electric Signal In Neurons, Kevin J. Roberts

All Graduate Reports and Creative Projects, Fall 2023 to Present

Neurons in humans and other species transmit information by sending electric signals via axons. This process relies on the generation and propagation of action potentials—rapid changes in the membrane potential of the axon. Understanding the mechanisms of action potentials, including how they are generated and influenced by the axon geometry and material parameters, is crucial for gaining insight into neurological diseases such as Alzheimer’s and Multiple Sclerosis (diseases highly correlated to demyelination). In this work, we review and summarize mathematical models for signal transmission–including the classical Hodgkin-Huxley model, the Single Cable (SC) model, and the Double Cable (DC) model. We …

Enduring Efffects Of Juvenile Fluoxetine Exposure On Serotonin Transporter Expression Within The Hippocampus And Prefrontal Cortex Of Male C57bl/6 Mice, Daniel Eduardo Calvo

Open Access Theses & Dissertations

Prescription rates of fluoxetine, the most dispensed selective serotonin reuptake inhibitor, have been rising among the juvenile population. Since adolescence is a critical developmental period in which the brain undergoes pruning, chronic increases in serotonin levels may lead to long-term neurobiological changes in brain regions responsible for emotional regulation. Thus, using mice as a model system, this thesis evaluated how adolescent fluoxetine exposure (AFE) influences the expression of serotonin transporters (SERT) in the adult hippocampus and prefrontal cortex. To do this, postnatal day (PD)-35 male C57BL/6 mice were administered with fluoxetine (250 mg/l in their drinking water) for 15 consecutive …

Mindreading And Embodiment: Beyond Mirror Neurons., Sanad Al Khatib

College of Arts & Sciences Senior Theses

This paper examines the question: how do we figure out what other people are thinking and why they act as they do, or put differently, how is it that we can read minds in daily life? For decades, the dominant view held that we explain and predict other people’s behavior by attributing to them mental states such as beliefs, desires, and intentions, represented symbolically in the brain. The embodied simulation model challenges this view, proposing that understanding others primarily relies on mirror neurons that activate both when we perform an action and when we observe someone else performing it. This …

Examing Fear Conditioning/Extinction And The Role Of The Amygdala In Human Neuroimaging., Olivia Cook

Electronic Theses and Dissertations

Fear plays a crucial role in survival but can lead to psychological disorders when dysregulated. Fears can be innate due to evolutionary relevance or learned through associative processes, where predictive accuracy of threat is pivotal. Disruptions in fear neurocircuitry contribute to anxiety disorders, characterized by heightened activation and impaired learning. Fear conditioning and extinction paradigms based on classical Pavlovian conditioning have been used to study mechanisms underlying fear learning. Using this experimental model, fear networks in rodents have been described in detail with clear distinction between conditioning and extinction neural functioning. Yet, there is no consensus on the neurobiological processes …

Visualizing The Fretboard: Arpeggiated Patterns, Muscle Memory, And Neurocognitive Strategies For The 5-String Electric Bass, Matthew Alexander Woisin

Electronic Theses and Dissertations

Proficient navigation of the 5-string electric bass requires a comprehensive mastery of various techniques and a solid understanding of music theory. This includes a detailed grasp of arpeggios, chord extensions, and the development of deeply ingrained muscle memory for precise execution. This thesis introduces a structured methodology that refines existing fretboard visualization techniques and applies a unique manner of fretboard mapping, offering a more precise framework for comprehending and unlocking the full range of the instrument. By drawing insights from music theory, music education, cognitive science, neuroscience, and technology this approach is achieved by synthesizing research on visual pattern recognition, …