Neuroscience and Neurobiology Commons^™

Genetic Heterogeneity In Schizophrenia And Contribution Of Context To Vowel Recognition, Eva Childers

Dartmouth College Ph.D Dissertations

This dissertation is composed of three chapters that address two distinct topics. Chapter 2 addresses the use of consonantal context in vowel perception. Previous studies have demonstrated that context is important for vowel identification, however, this effect may be an artifact of stimuli production. To address this potential confound, we used stimuli extracted from an audiobook and asked subjects to identify vowels encased in consonants and isolated by themselves. We show that subjects had improved vowel identification when the vowel is presented with a consonantal framing, suggesting there is information contained in the surrounding context that is important for phoneme …

Mirnas Levels In A Streptozocin Model Of Alzheimer’S Disease, Nada Moustafa

Theses and Dissertations

Dementia entails a progressive decrease in cognitive functions, with 50%-75% of cases attributed to Alzheimer’s disease (AD); an aging-associated condition characterized by the build-up of tangled phosphorylated Tau (p-Tau) protein and beta-amyloid (Aβ) depositions. Sporadic AD (sAD) is multifactorial in nature, resulting from a combination of environmental and genetic predisposing factors. Type 2 diabetes mellitus (T2DM) is a leading risk factor for dementia, and deregulation of brain glucose metabolism is associated with early cognitive affection in sAD. Thus, the diabetogenic agent Streptozotocin (STZ) is used to experimentally create an AD model in animals (STZ-induced sAD), in which abnormalities in cerebral …

Norepinephrine Regulation Of Spatial Memory Using The Barnes Maze In Male And Female Rats, Serena Simpson, Ali Gheidi Phd, Nareen Sadik, Cameron J. Davidson Phd, Shane A. Perrine Phd

Medical Student Research Symposium

The role of norepinephrine (NE) in learning and memory has been extensively studied, yet its contribution remains to be clarified. This study aimed to investigate the role of NE on spatial learning and memory in female and male rats using a Barnes maze assay. We used N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), a specific noradrenergic neurotoxin that can cross the blood brain barrier, to deplete NE stores. We hypothesized that brain NE ablation would attenuate spatial learning and memory in rats. Loss of NE by DSP-4 was determined by measuring NE (and dopamine and serotonin) levels in several brain regions using HPLC. For the …

Hiding Behind The Title: Bridging The Gap Between Identity And Leadership Through Neuroscience, Emotional Intelligence And Ethical Management, Alicia S. Huddleston

College of Education Theses and Dissertations

Leadership is the key determinant in the success of any organization, and leaders have an immeasurable impact on the lives and performances of those they have been entrusted to develop, support and lead. School principals are an integral part of the leadership tapestry within society and many people have been impacted by a school principal. Often enough, there are individuals who lead with or behind their title versus understanding first who they are intrinsically, and then working through those dynamics to effectively lead their own lives. When leaders are able to do this, then and only then are they equipped …

Examining Limbic Sexual Dimorphisms In Schizophrenia, Kennedy S. Madrid

Undergraduate Honors Theses

Schizophrenia is a mental disorder that affects a significant number of individuals in the United States and can have numerous different symptoms. Recently, interest in the differences between the neuroanatomy of individuals with schizophrenia and individuals without schizophrenia has emerged, specifically the sexual dimorphism in individuals with schizophrenia. This study aimed to gain a better understanding of the sexual dimorphisms of two structures in the limbic system: the hippocampus and amygdala. Data was harmonized and analyzed from two datasets to determine the sexual dimorphic factor of these structures in healthy controls and individuals with schizophrenia. Demographic features were also taken …

Mpc-Stanet: Alzheimer’S Disease Recognition Method Based On Multiple Phantom Convolution And Spatial Transformation Attention Mechanism, Yujian Liu, Kun Tang, Weiwei Cai, Aibin Chen, Guoxiong Zhou, Liujun Li, Runmin Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Alzheimer's disease (AD) is a progressive neurodegenerative disease with insidious and irreversible onset. The recognition of the disease stage of AD and the administration of effective interventional treatment are important to slow down and control the progression of the disease. However, due to the unbalanced distribution of the acquired data volume, the problem that the features change inconspicuously in different disease stages of AD, and the scattered and narrow areas of the feature areas (hippocampal region, medial temporal lobe, etc.), the effective recognition of AD remains a critical unmet need. Therefore, we first employ class-balancing operation using data expansion and …

The Effects Of Floral Attributes And Conspecifics On Bumble Bee Forager Memory, Lucas Lauter, Tiffany Dinh

Undergraduate Research Symposium

What do bees remember about flowers? These memories are important for both bees and flowers. The bees have better foraging success and gain more nectar and pollen from flowers when they remember the most rewarding flower types. More memorable flowers will be visited more frequently, resulting in more successful pollination for the plant. At the same time, bees can also learn about flowers from other bees and may remember this information differently. We are training and testing three floral cues and a single social cue to see how the different types of cues affect their learning and memory of rewarding …

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 …

Mapping Auditory And Vestibular Response Neurons In The Optic Tectum Of Larval Zebrafish, Erika Marks, Arminda Suli

Undergraduate Honors Theses

Cellular mapping of the sensory receptive fields of brain structures is a critical step in understanding function and dysfunction in development. Deficits in the ability to receive, process and integrate the senses leads to difficulties recognizing and responding appropriately to stimuli. To understand how the senses are integrated, it is first necessary to map the neurons receptive to inputs from individual senses. The optic tectum of zebrafish is a structure known for its homology to the superior colliculus of mammals and is a center of multisensory integration – including visual, auditory, and somatosensory stimuli. However, the microcircuitry of this important …

Age-Dependent White Matter Disruptions After Military Traumatic Brain Injury: Multivariate Analysis Results From Enigma Brain Injury, Heather C. Bouchard, Delin Sun, Emily L. Dennis, Mary R. Newsome, Seth G. Disner, Jeremy Elman, Annelise Silva, Carmen Velez, Andrei Irimia, Nicholas D. Davenport, Scott R. Sponheim, Carol E. Franz, William S. Kremen, Michael J. Coleman, M. Wright Williams, Elbert Geuze, Inga K. Koerte, Martha E. Shenton, Maheen M. Adamson, Raul Coimbra, Gerald Grant, Lori Shutter, Mark S. George, Ross D. Zafonte, Thomas W. Mcallister, Murray B. Stein, Paul M. Thompson, Elisabeth A. Wilde, David F. Tate, Aristeidis Sotiras, Rajendra A. Morey

Center for Brain, Biology and Behavior: Papers & Publications

Mild Traumatic brain injury (mTBI) is a signature wound in military personnel, and repetitive mTBI has been linked to age-related neurogenerative disorders that affect white matter (WM) in the brain. However, findings of injury to specific WM tracts have been variable and inconsistent. This may be due to the heterogeneity of mechanisms, etiology, and comorbid disorders related to mTBI. Non-negative matrix factorization (NMF) is a data-driven approach that detects covarying patterns (components) within high-dimensional data. We applied NMF to diffusion imaging data from military Veterans with and without a self-reported TBI history. NMF identified 12 independent components derived from fractional …

The Role Of Reported Affective Symptoms And Anxiety In Recovery Trajectories After Sport-Related Concussion, Bernadette A. D'Alonzo, Abigail C. Bretzin, Douglas J. Wiebe, Ivy League–Big Ten Epidemiology Of Concussion Study Investigators, Arthur C. Maerlender, Cary R. Savage

Center for Brain, Biology and Behavior: Papers & Publications

Background: There is growing awareness and clinical interest in athletes with affective symptoms after sport-related concussion (SRC), as these symptoms may contribute to overall symptoms and represent a modifiable risk factor of longer recovery. However, evidence of their effects on the entire return-to-play (RTP) trajectory, particularly among women and men, is limited.

Purpose/Hypothesis: To examine the relationship between affective symptom reporting and RTP progression after SRC among a cohort of Division 1 student-athletes. We hypothesized that those endorsing affective symptoms, specifically nervous-anxious symptoms, spend more time in RTP progression and recovery.

Study Design: Cohort study; Level of evidence, 3.

Methods: …

Utility Of The Motivation To Change Lifestyle And Health Behaviors For Dementia Risk Reduction Scale (Mclhb-Drr) Based On A North American Sample, Angelina E. Witbeck

Dissertations

As the population ages, the prevalence rates of dementia continue to increase. Without a cure or promising treatment for dementia, the best course of lowering the prevalence rates of dementia is through preventative measures. Through an electronic survey, the study utilized the MCLHB-DRR scale to determine whether (1) gender, age, educational background, and socioeconomic status will impact the motivational factors to change lifestyle and health behaviors to reduce the risk of developing dementia and (2) direct experiences with individuals that have a dementia diagnosis are likely to impact one's motivational factors to change lifestyle and health behaviors to reduce the …

Improving An Ssvep-Based Brain Computer Interface Speller, Mac Kenzie J. Frank

Honors Theses

A brain-computer interface (BCI) is a novel technology that creates direct assistive communication between the brain and a computer. While numerous electroencephalogram (EEG) based BCI-speller applications have been used for communication by adults with physical disabilities; few BCI studies have included children, and none using BCI spellers. A pilot study of a developmentally-appropriate EEG-based speller-storybook interface that relied on steady-state visual evoked potentials (SSVEPs) by two pediatric users with quadriplegic cerebral palsy showed limited speller reliability (E. Floreani, personal communication, September 30, 2021). In the pilot study, the alphabet was parsed between three boxes, each flashing at a different rate …

Testing An Overtraining Protocol For Fear Learning In Humans, Gordon M. Haskell

Dissertations, Theses, and Capstone Projects

Successful regulation of fear memories is a fundamental tenet to the exposure-based therapies often employed by mental health professionals for individuals with PTSD, phobias, and other anxiety disorders. Consequently, the efficacy of these treatment methodologies is largely dependent on the strength of the fear memory, as stronger memories are often characterized by an increased resistance to extinction and heightened fear recovery. However, there is little consensus within the scientific community regarding how to effectively maximize fear memory strength in human studies, and the literature exploring the impact of variability in acquisition parameters on memory strength is sparse. Here, we tested …

The Effects Of Near-Threshold Color Manipulation On Perceptual Decision-Making And Confidence Report, Trevor Caruso

Dissertations, Theses, and Capstone Projects

Confidence measures are sometimes used to index awareness below a participant’s criterion for what counts as being subjectively aware of a stimulus or stimulus property. If confidence ratings index awareness below subjective thresholds, then one might be tempted to use confidence ratings in place of subjective reports of whether a stimulus/stimulus property was “seen” or “unseen”. As such, a dissociation of confidence from performance may be construed as a dissociation of subjective awareness from objective task performance. This methodology has been used as supporting evidence for blindsight in typical observers (Balsdon and Azzopardi 2015; Peters and Lau 2015; Peters et …

Withdrawal From Voluntary Oral Methamphetamine Reveals Female Specific Susceptibilities To Behavioral Deficits And Neurochemical Perpetuators Of Neurotoxicity And Drug Seeking Behavior, Nicoletta K. Memos

Dissertations, Theses, and Capstone Projects

MA is a potent, highly addictive psychomotor stimulant known to produce neurotoxic effects on the brain leading to neurological impairments^1-6 characterized by neurodegeneration of dopaminergic fibers, cell bodies and pathways, as well as brain regions such as the hippocampus, frontal cortex, and midbrain^1,5.

In MA addiction, women are more vulnerable to the behavioral and cognitive effects of MA compared to men. Adult human literature reveals gender differences in usage patterns and women demonstrate increased vulnerability to the neurotoxic effects and health effects of MA use. Women begin drug use at an earlier age, escalate drug use quicker, …

The Impact Of Focused Attention And Opening Monitoring Meditation Styles On Attention, Jennifer Wheary

Dissertations, Theses, and Capstone Projects

Mindfulness meditation – often broken down into two distinct types, focused attention (FA) and open monitoring (OM) – has been associated with a range of affective and attentional benefits. Using an attentional blink (AB) paradigm that demonstrated improved attention for novice FA meditators, we explored whether novices who engaged in a single, brief bout of meditation exhibited any differences in alpha or theta power during meditation, and whether these differences were apparent by meditation type. In the AB paradigm, participants are asked to identify two targets, T1 and T2, which are separated by 200-500 ms. Our results showed no significant …

Investigating Steady State Visually Evoked Potentials As A Novel Biosignature For Anxiety-Related Attention Bias, Elizabeth R. Davis

Dissertations, Theses, and Capstone Projects

Anxiety-related attention bias (AB), a type of cognitive bias underlying the development and maintenance of anxiety disorders, is typically defined as exaggerated attention towards threat; however, some individuals also demonstrate AB away from threat and in some instances, no detectable AB at all. Debate about the reliability and validity of AB behavioral measures has prompted examination of additional assessment methods. Neurophysiological methods, such electroencephalography (EEG), have yielded encouraging early findings. The steady-state visually evoked potential (SSVEP), a measure of selective visual attention derived from EEG, holds promise as a biosignature for AB. Research documents heightened SSVEP power to emotionally salient …

Genetic Circadian Mosaics And The Clock Network’S Contributions To Sleep, Lukasz Widziszewski

Dissertations, Theses, and Capstone Projects

Circadian rhythms are physiological and behavioral changes which follow a 24-hour cycle. Drosophila Melanogaster’s circadian clock neuronal network (CCNN) has been identified and several subpopulations have been characterized based on previous studies; the classifications of subpopulations of neurons within the CCNN are based on a return of anticipatory locomotor activity preceding the two daily light transitions (Lights on = dawn/Lights off = dusk). The neurons responsible for the return of anticipatory morning locomotor activity have been referred to as the M-cells, the group of neurons known to rescue evening anticipatory locomotor activity have been termed the E-cells. In this …

One-Stage Blind Source Separation Via A Sparse Autoencoder Framework, Jason Anthony Dabin

Dissertations

Blind source separation (BSS) is the process of recovering individual source transmissions from a received mixture of co-channel signals without a priori knowledge of the channel mixing matrix or transmitted source signals. The received co-channel composite signal is considered to be captured across an antenna array or sensor network and is assumed to contain sparse transmissions, as users are active and inactive aperiodically over time. An unsupervised machine learning approach using an artificial feedforward neural network sparse autoencoder with one hidden layer is formulated for blindly recovering the channel matrix and source activity of co-channel transmissions. The BSS sparse autoencoder …