Neurophysiological Signatures Of Perceived Control In The Human Brain: An Electroencephalography Study, Megan Staehling

Honors Theses

Perceived control is defined as the belief that one’s actions can influence the outcomes in the environment. It plays an important role in decision-making, motivation, and emotional regulation. Previous studies suggest that perceived control shapes how the brain processes both reward and punishment stimuli. However, the neural mechanisms underlying this process are still unclear. The present study examined the neurophysiological correlates of perceived control during a decision-making task. Electroencephalography (EEG) was used to record the neural activity of twenty-nine undergraduate students while they completed the Choice Task. Participants associated visual cues with different levels of control over trials involving monetary …

Neuroprotective Effects Of Estradiol And Genistein And Interactions With Aromatase Inhibitions Post Cerebellar Lesion In Male Zebra Finches, Grace E. Thompson, Anthony P. Irovic

Honors Theses

Across vertebrates, peripheral and brain-derived estradiol (E₂) promotes neuroplasticity. After injury, E₂ can be derived locally from testosterone via aromatase (AROM), an enzyme that is upregulated in glia at the site of neural injury. E₂disrupts testicular function and elevates cancer and stroke risk, primarily via binding to estrogen receptor alpha (ER α). Genistein (GEN), a phytoestrogen, is similar to E₂ but binds preferentially to estrogen receptor beta (ER β). It may offer neuroprotection without adverse effects of E₂. We used adult male zebra finches (ZF) to model neuroprotective effects of E_{2 …}

Beat Behind The Bark: Investigating The Effects Of Music Tempo On Canine Physiological And Psychological States, Marley Lanier

Honors Theses

This study explores how the tempo of music, measured in beats per minute (BPM), affects dogs' heart rate and oxytocin levels, adding to past research that shows that music affects physiological and behavioral states in dogs. Being able to understand these effects holds practical implications for improving overall well-being in canines in environments such as homes, shelters, and clinical environments. Using a within-subjects design, the dogs were exposed to slow and fast versions of one instrumental track, along with a white noise baseline condition before each randomized condition. Heart rate was recorded continuously throughout the session, and oxytocin saliva samples …

Development Of A Preclinical Model That Can Be Used To Test Novel Therapeutics For The Treatment Of Mild And Moderate Traumatic Brain Injury, Hayden Anderson

Honors Theses

Traumatic Brain Injury (TBI) occurs when a foreign object induces damage to the skull and brain through a forceful blow or whiplash. It is one of the most frequent injuries in the United States, with approximately 250,000 cases of different levels occurring annually. It is well known that severe TBIs can result in persistent physical, cognitive, and socioeconomic consequences and the timing of treatment following this injury can play a critical role in the ultimate outcome. It would be beneficial to develop a safe therapeutic that could be administered rapidly after impact and improve the recovery of the patient. However, …

The Role Of Presynaptic Proteins In Alcohol Sensitivity And Tolerance, Madhumitha Gundluru

Honors Theses

Mammalian Unc13 (Munc13) and Drosophila Unc13 (Dunc13) are presynaptic active zone proteins essential for synaptic vesicle docking and priming in a neuron. Alcohol binds to the C1 domain of Munc13, which inhibits DAG binding. The reduction in DAG binding by Munc13 decreases the probability of vesicle fusion with the membrane, decreasing neurotransmitter release. Heterozygotes for a Dunc13 loss-of-function allele are behaviorally resistant to alcohol, physiologically resistant to alcohol, molecularly resistant to alcohol, and self-administer significantly more alcohol than control flies. Therefore, genetically reducing Dunc13 mimics a state of alcohol tolerance in the fly. The two main Dunc13 isoforms, Dunc13A and …

Claiming More To Cope: Does Ostracism Increase Overclaiming?, Katy Q. Chen

Honors Theses

In a pre-registered online study, we investigated the relationship between ostracism and overclaiming. Ostracism is the act of deliberately or unintentionally excluding and ignoring others. Overclaiming refers to the behavior of exaggerating one’s knowledge or familiarity with specific topics, often as a way of attempting to present oneself as more knowledgeable or competent than one actually is. Drawing from the temporal need-threat model, we hypothesized that ostracized individuals, as a compensatory response, would likely overclaim more compared to included individuals. This online study simulated a work experience where participants were asked to answer questions about their work-related experiences and opinions. …

Sliding Window Method For Simulating Action Potentials In Axons, Hayden Reed

Honors Theses

ABSTRACT Hodgkin and Huxley’s nonlinear partial differential equations model the excitation and propagation of action potentials in neurons, and there have been numerous attempts at finding the best numerical solution method. This thesis proposes a novel approach to solving these equations: the Sliding Window method, in which a fixed sub-interval is found through capturing the signal’s head and tail. The system is then solved on the sub-interval instead of the entire interval. Using the Sliding Window technique also involves implementing the backward and forward Euler methods and the finite difference method. It will be demonstrated that, in utilizing the Sliding …

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 …

Distracted But Still Listening: How Cognitive And Perceptual Load Affect Multisensory Integration, Eddie Lee

Honors Theses

There is an ongoing debate about whether multisensory integration (MSI) occurs automatically and before attention is allocated or if multisensory integration occurs after attention is allocated and is subject to top-down attentional control. A recent study investigated this by manipulating the availability of attentional resources in a dual-task paradigm, finding that when the demands of the secondary task increased, susceptibility to the Sound-Induced-Flash-Illusion, a non-speech audiovisual illusion, also increased (Michail & Keil, 2018). This was taken as evidence for the role of post-attentive, top-down control during MSI. In the present study, we extend this logic to explore the role of …

Early Developmental Exposure To Δ9-Tetrahydrocannabinol Causes Latent Behavioral, Growth, And Bioenergetic Effects In Danio Rerio, Astra Hahm

Honors Theses

Early developmental exposure to Δ9-tetrahydrocannabinol causes latent behavioral, growth, and bioenergetic effects in Danio rerio

(Under the direction of Dr. Kristine Willett)

Δ9-tetrahydrocannabinol (Δ9-THC) is used during pregnancy to mitigate symptoms such as nausea, pain, and insomnia. It is established that Δ9-THC exposure early in life causes adverse effects in children’s development including behavioral disorders. Our goal was to determine the latent and generational impacts on growth, behavior, and mitochondrial bioenergetics following exposure to Δ9-THC. Wildtype (5D) zebrafish were exposed to 0 (0.05% DMSO), 0.08, 0.4, or 1 µM Δ9-THC from 6-96 hours post-fertilization (hpf), then subsequently raised in clean …

The Role Of Oncomodulin In The Central Nervous System Inflammation, Evan Paltjon

Honors Theses

Acoustic overexposure in mice leads to an excess of calcium influx in outer hair cells (OHCs) and causes permanent hearing loss due to death of OHCs. Oncomodulin is a parvalbumin calcium buffering protein located in OHCs of the cochlea. Early pilot studies indicate that genetic deletion of OCM results in immune-related pathology throughout the cochlea. Why and how this occurs is unknown. Studies in wild type (WT) and OCM knockout (KO) mice demonstrate greater numbers of immune cells are associated with noise exposure in an OCM knockout than in WT. Expression of toll-like receptor 4 (TLR4) leads to the recruitment …

Sleep Duration Is Associated With Caudate Volume And Executive Function, Nicole Jones

Honors Theses

The ineligible role of the caudate nucleus in sleep has been implicated throughout multiple scientific studies. Previous literature has shown that greater caudate volume is associated with longer habitual sleep duration in older adults- ranging from 55 years of age and up. However, the association between sleep duration and caudate volume remains unknown in the younger population. In this study, we examined the caudate volume in youth to older adults (10 to 85 years old) with a greater sample size (N=464) to increase statistical power. The volumetric size of the caudate nucleus showed significantly positive association with habitual sleep duration, …

The Interhemispheric Auditory Tract Connectivity And Autism Spectrum Disorder, Josie Long

Honors Theses

Individuals with autism spectrum disorder (ASD) can have abnormal responses and hypersensitivity to sounds (Haesen et al., 2011). ASD is also related to inattentive, hyperactive, and impulsive behaviors (Bradley & Isaacs, 2006). One study by Stansberry et al. (2022) found that a higher fractional anisotropy (FA) of interhemispheric auditory white matter is associated with higher impulsivity. Our study examined the interhemispheric auditory tract (IAT) to determine whether it is impacted by ASD. We used diffusion tensor imaging (DTI) data from Autism Brain Imaging Data Exchange utilizing two datasets so that we could replicate primary findings. We first isolated the IAT …

All The Rage: Assessing The Age/Rage Signaling Pathway’S Effects On Healthspan And The Physiological Processes Of Aging, Brandon Ashmore

Honors Theses

Advanced glycation end products (AGEs) are protein, lipid, or nucleotide molecules that have been combined with sugars through nonenzymatic, irreversible glycation and oxidation reactions. Their accumulation in the body has been associated with the natural aging process and a wide range of pathologies, including chronic inflammation, sustained oxidative stress, diabetes, neurodegenerative diseases, atherosclerosis, and cancer. Their interaction with the receptor for advanced glycation end products (RAGE) has been linked to several proinflammatory signaling pathways associated with neurotoxicity and vascular lesions. While some research has been done on the possible health benefits of RAGE inhibition to extend lifespan, our study hopes …

The Effects Of Acute Exercise On Memory: Considerations Of The Testing Effect, Philip Christian

Honors Theses

This study had three main objectives. The first objective was to determine whether or not there was evidence of a testing effect being present when a short-term memory assessment is included along with a long-term memory assessment. The second objective was to determine whether acute exercise can improve long-term memory recall over a control condition. The third objective was to determine if the potential effects of acute exercise on long-term memory are confounded by the inclusion of a short-term memory assessment. Participants were 54 undergraduate students at the University of Mississippi, with an age range of 18-22 years old. Participants …

Neuronal Effects Of Cocaine In An Animal Model Of Social Stress: Analysis Of Neuronal Recordings, Eboni Eddins

Honors Theses

Studies that use Intermittent (episodic) Social Defeat (ISD) in rats demonstrate that ISD increases cocaine-self administration several weeks after the end of the adverse experience and suggest that a history of social stress makes individuals more vulnerable to substance abuse in the long term. The medial prefrontal cortex (mPFC) plays a key role in regulating drug-seeking behavior. The present study investigates whether ISD enhances the response of mPFC neurons to cocaine. Male Long Evans rats (3-4 months) were implanted with electrode arrays in the mPFC (prelimbic area) and divided into two groups (Control, n= 4; Stress, n= 4). They were …

Effects Of Cannabichromene On Pain And Neuroinflammation In Hiv-1 Tat Transgenic Mice, Sydney Wheeler

Honors Theses

HIV-1 TransActivator of Transcription (Tat) is a vital regulatory protein involved in HIV replication and implicated in development of HIV-associated pain and neurocognitive deficits. Tat is thought to contribute to these pathologies through proinflammatory pathways. Developing mechanisms to curb Tat-mediated inflammation is a key step in improving the quality of life of those living with HIV. Both recreational and medicinal cannabis use is prevalent among many people living with HIV; given this prevalence and the perceived anti-inflammatory benefits of cannabis use, it is important to investigate how chemical constituents of cannabis may impact HIV. In the present study, the effects …

The Role Of The Pcc And Acc In Autism Spectrum Disorder: A Functional Connectivity Study, Claudia Gonzalez

Honors Theses

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that impacts behavior control and social skills. Currently, ASD diagnoses are largely qualitative; thus, having more quantitative means of identification would aid in earlier diagnosis of ASD. However, more research is needed to pinpoint observable neurobiological markers of ASD. Our study focused on the posterior cingulate cortex (PCC) due to past evidence suggesting its involvement in ASD symptomatology. The PCC has been linked to behavioral control and executive functioning. Moreover, previous studies support executive functioning’s responsibility for the repetitive and restricted behaviors (RRB) in ASD.

Method: Our study sought to …

Expression And Purification Of The Bacterial Protein Curli Csga And Its Cross-Interactions With Amyloid-B, Leah Grace Cantrell

Honors Theses

One of the main causes of neurodegenerative diseases is aggregation of amyloid proteins that are toxic to the neurons. Proteins like amyloid-β (Aβ) and α-syneuclein (α-syn) form hallmark aggregate lesions that contribute to pathological processes in the brain in Alzheimer and Parkinson’s patients, respectively. Recent ground-breaking studies have suggested a link between the microbiota of the gut and neurodegenerative diseases, called the “gut-brain axis.” It has been long known that the protein, CsgA found in many enteric bacteria, forms amyloid fibers of its own called Curli. Curli fibrils are a structural component of bacterial colonies and maintain the integrity of …

Investigating The Neuroprotective Effects Of Cannabinoids And Insulin-Like Growth Factors On Glia With Induced Inflammation, Caleb Bloodworth

Honors Theses

Chronic inflammation is a driver of numerous neurodegenerative diseases that reduce quality of life for affected individuals. Non-psychoactive cannabinoids have begun to gain more interest in the world of anti-inflammatory medicine for chronically ill patients. Along with these cannabinoids, insulin-like growth factor-1 has been examined for its association with downregulation of inflammation. Our research aimed to investigate how neuroglia are affected by treatment with cannabinoids or IGF-1 in the face of inflammation from HIV-1 protein, Tat, or lipopolysaccharide (LPS). Preliminary studies in our laboratory showed that neither cannabinoids or IGF-1 treatment altered astrocyte morphology or overall astrocyte viability under baseline …

The Effects Of Astrocytic Derived Insulin-Like Growth Factor (Igf-1) On Cognition And Astrocytes, Destiny Wilson

Honors Theses

Insulin-like growth factor 1 (IGF-1) is a neuroendocrine signaling hormone that plays a vital role in growth and development, as well as learning and memory. Inhibition of this hormone results in cognitive impairments like those seen with age-related decline. While a majority of research has focused on the role of IGF-1 on neurons, the role of astrocytes still needs to be explored. Our research investigates how astrocytes and cognition are affected as a result of direct regulation of localized IGF-1 production in early development and after puberty. Preliminary studies in our laboratory established a connection between IGF-1 and glial fibrillary …

The Effects Of Acute Exercise Intensity On Retrieval-Induced Forgetting, Geoffrey Reliquias

Honors Theses

Previous research has indicated that aspects of cognitive inhibition may be enhanced after engaging in acute exercise. Notably, cognitive inhibition has been theorized as a potential mechanism for a form of active forgetting known as retrieval-induced forgetting (RIF). Given that cognitive inhibition may explain the RIF phenomenon, and is also influenced by exercise, it is plausible that acute exercise may directly influence RIF. To our knowledge, only one study has examined whether acute exercise has an effect on RIF. The findings of that study did not find a statistically significant effect for RIF; however, we believe that the rather small …

Effects Of Acute Exercise Intensity On Behavioral Pattern Separation, Sarah Amitin

Honors Theses

Prior work has demonstrated that acute exercise can improve memory performance. Less research, however, has determined whether this beneficial effect occurs through exercise reducing the influence of related or interfering stimuli. Thus, the present experiment evaluated if acute exercise can improve memory by reducing the interference of similar or conflicting information. A mnemonic similarity task was used where participants studied pictures of a wide variety of objects. The retrieval portion of the task displayed a set of objects in which they had to identify as old (already studied), new, or similar. The list of objects in the retrieval phase had …

Effects Of Music Exposure On Autobiographical Memory In Alzheimer's Patients: A Systematic Review And Meta-Analysis, Gregory Vance

Honors Theses

The progression of Alzheimer’s disease is primarily characterized by a loss of memory concerning past events, as well as a lack in ability to create new memories. While this spans across many subsets of memory, such as recognition, recall, and autobiographical memory, there seems to be a lesser impact on musical memory in those with Alzheimer’s. Multiple studies have suggested that exposure to music and introduction of music therapy can even improve other aspects of memory in Alzheimer’s patients. This systematic review and meta-analysis sought to examine the relationship between music exposure and autobiographical memory specifically. A pool of electronic …

Efficacy Of Δ-9-Tetrahydrocannabinol For Hiv-Related Neuropathic Pain, Kaia Horne

Honors Theses

Despite the availability and success of antiretroviral therapeutics, ~30% of patients living with HIV experience neuropathic pain that is often intractable. The mechanisms are not known, but there is evidence to support a role for the HIV virotoxins, Tat and/or gp120, which can damage or degenerate neurons and peripheral nerves. One mechanism by which Tat and gp120 promote nerve damage involves the stimulation of proinflammatory cytokine production from immune cells which can damage or kill bystander cells. Notably, compounds found in Cannabis exert anti-inflammatory effects and many studies report HIV patients to consume more marijuana than seronegative individuals. When people …

Alzheimer's Disease: A Comprehensive Review Including Personal Experience From Retirement Home Patients, Sydney Fox

Honors Theses

Alzheimer’s Disease is a neurodegenerative illness and disease, the most common type of dementia, and the sixth leading cause of death (Sá et al., 2012). The disease was discovered in 1906 and named after Dr. Alois Alzheimer, a psychiatrist and neuropathologist. Over time, a variety of hypotheses have developed regarding the cause behind this multifactorial disease, and these will be disclosed in a later section. Nonetheless, the disease was first observed in changes of the brain tissue of a woman who was said to have die from an unusual mental illness with many abnormal bumps. These bumps are now recognized …

Effects Of Acute Exercise Intensity On Memory: Considerations Of Timing And Aerobic Endurance, William Meyers, Caroline Loeb, Mary Collins West, Bailey Bass

Honors Theses

The primary objective of this study was to find the optimal acute exercise intensity and post-exercise recovery time to enhance memory retention. A secondary objective of study was to evaluate the influence of aerobic endurance on memory and whether endurance capacity interacts with exercise intensity and post-exercise recovery period to influence memory performance. Participants were 54 undergraduate and graduate students at the University of Mississippi, with an age range of 18-23 years. Participants completed 13 visits in total. The first visit evaluated their aerobic endurance, with the remaining 12 visits including a 3 (Intensity: Control, Moderate, Vigorous) by 4 (Post-Exercise …

Characterizing Cellular Stress, Hippocampal Function, And Behavior In A Novel Rat Model Of Alzheimer's Disease, Anne A. Schulman

Honors Theses

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder that affects over 5 million individuals in the United States alone. While AD is primarily thought of as a disease that destroys neural networks required for memory recall and formation, AD also cause impairment in emotional regulation, cognitive flexibility, and executive function pathways. The cause of AD is unknown; however, the allele ApoE4 has been identified as a risk factor for the onset of AD. ApoE4 provides a valuable opportunity to study AD through animal models. This thesis utilized a human ApoE4 transgenic rat model (hApoE4) to investigate the biological and behavioral …

Microglia Polarize In Response To Transactive Response Dna-Binding Protein-43 (Tdp-43) And Display Partial Recovery After Removal Of The Stimulus, Alicen Wilcox

Honors Theses

The proper response to protein signals is necessary for a healthy central nervous system (CNS), and protein dysregulation is a feature of neurodegenerative diseases. Transactive response DNA-binding protein-43 (TDP-43) is an intranuclear protein, but mislocalization is associated with amyotrophic lateral sclerosis (ALS). TDP-43 is released into the extracellular space where it is sensed by microglia, the CNS-resident immune cells. Our data and the literature suggest that microglia respond to TDP-43 dysregulation by increasing CNS inflammation. The goal of this study was to determine the impact of TDP-43 on microglial function and the extent to which microglia recovery. To study the …

Systematic Review Of Race/Ethnicity In Parkinson's Disease, Amia Fisher

Honors Theses

The goal of this study was to examine race/ethnicity with an emphasis on African Ancestry in Parkinson’s Disease (PD) through a systematic review. Out of 448 scholarly articles that were originally extracted from the search, 445 were excluded due to their irrelevance regarding race/ethnicity and African ancestry in PD. Three scholarly articles were obtained through a PubMed/MEDLINE search for the review. Amongst the three sources that were chosen, there were more than 450,000 participants with PD that ranged in ages 40-65+; each case of PD within these studies were reported from 1993-2005. The varying races/ethnicities of White/non-Hispanic White, Black/African American, …