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Articles 1 - 30 of 94

Full-Text Articles in Neuroscience and Neurobiology

Methodology To Investigate Protein-Protein Interactions Of Jun During Neuronal Differentiation Of Pc12 Cells, Heather L. Leskinen Dec 2023

Methodology To Investigate Protein-Protein Interactions Of Jun During Neuronal Differentiation Of Pc12 Cells, Heather L. Leskinen

Theses and Dissertations

In humans and other mammals, injury to the central nervous system (CNS) can cause a permanent loss of neuronal function, leading to cognitive defects, limb paralysis, and other neurological disabilities. In contrast, studies have shown that some non-mammalian vertebrates like zebrafish, have the remarkable ability to functionally regenerate axons after CNS injury by reactivating and sustaining the expression of regeneration-associated genes (RAGs). Some RAGs encode transcriptional regulators that dimerize to control downstream gene expression necessary for functional axonal recovery. Our lab has previously identified Jun as an important transcriptional regulator of regeneration after optic nerve injury in zebrafish. After axon …

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Potential Moderating Impact Of Circulating Endocannabinoids On Resting State Networks And Post-Traumatic Stress Disorder, Emily Anne Albertina Dec 2023

Potential Moderating Impact Of Circulating Endocannabinoids On Resting State Networks And Post-Traumatic Stress Disorder, Emily Anne Albertina

Theses and Dissertations

Introduction: Traumatic injury increases risk for long-term adverse outcomes such as the development of post-traumatic stress disorder (PTSD). Research has found that risk for the development of PTSD after such an injury varies depending on individuals’ race/ethnic group and sex. Although prior work has explored relationships between injury and PTSD in these groups utilizing imaging paradigms (e.g., resting state functional connectivity) and biological paradigms (e.g., the endocannabinoid system), the relationship between these factors has been understudied. The present study explored the potential moderating effect circulating endocannabinoids may have on the relationship between resting state functional connectivity and post traumatic stress …

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Investigation Of The Role Of The G-Protein-Coupled Estrogen Receptor In Memory Consolidation In Gonadectomized Male Mice, Gustavo Dalto Barroso Machado Aug 2023

Investigation Of The Role Of The G-Protein-Coupled Estrogen Receptor In Memory Consolidation In Gonadectomized Male Mice, Gustavo Dalto Barroso Machado

Theses and Dissertations

Estrogens are cholesterol-derived hormones that play crucial physiological and pathological roles in both sexes and across the lifespan. Many research groups have replicated the beneficial roles of 17-beta-estradiol (E2), the most potent estrogen, in memory consolidation in the past decades, even though some mechanisms are still unclear. The rapid effects of E2 in memory formation are attributed to its binding to different estrogen receptors (ER), notably the intracellular receptors ER and ER, as well as the membrane ER called G protein-coupled estrogen receptor (GPER). Previous work from our laboratory demonstrated that acute post-training infusion of E2 into the dorsal hippocampus …

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The Biological Bases Of Political Attachment: Neurobiological Correlates Of Ideology And Partisanship, Carisa Bergner Aug 2023

The Biological Bases Of Political Attachment: Neurobiological Correlates Of Ideology And Partisanship, Carisa Bergner

Theses and Dissertations

To fully understand the foundations of political attachments in an increasingly polarized environment, political scientists must reconcile traditional theories of political attitudes and behavior with insight gained from neurobiological approaches. The purpose of this research is to investigate the neurobiological correlates of strength of political ideology and partisanship, as well as the neurobiological correlates of ideological and partisan orientation. To do so, both structural and functional neuroimaging analyses were conducted on a diverse sample of patients at a Level 1 Trauma Center. Results indicate that strong ideological attachment is significantly associated with decreased volume in the left insula, though partisan …

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Deciphering The Firing Patterns Of Hippocampal Neurons During Sharp-Wave Ripples, Kourosh Maboudi Ashmankamachali Dec 2022

Deciphering The Firing Patterns Of Hippocampal Neurons During Sharp-Wave Ripples, Kourosh Maboudi Ashmankamachali

Theses and Dissertations

The hippocampus is essential for learning and memory. Neurons in the rat hippocampus selectively fire when the animal is at specific locations - place fields - within an environment. Place fields corresponding to such place cells tile the entire environment, forming a stable spatial map supporting navigation and planning. Remarkably, the same place cells reactivate together outside of their place fields and in coincidence with sharp-wave ripples (SWRs) - dominant electrical field oscillations (150-250 Hz) in the hippocampus. These offline SWR events frequently occur during quiet wake periods in the middle of exploration and the follow-up slow-wave sleep and are …

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Probing Hippocampal Activity In Sleep, Sleep Deprivation, And Recovery Sleep, Bapun Giri Aug 2022

Probing Hippocampal Activity In Sleep, Sleep Deprivation, And Recovery Sleep, Bapun Giri

Theses and Dissertations

Long-term memories are established over several hours of sleep following their initial acquisition. Large-scale recordings from the hippocampus have revealed that neurons reactivate or `replay' wake-induced activity in subsequent sleep episodes, leading many to suggest replay as an underlying mechanism for sleep-mediated memory consolidation. In this dissertation, I describe experiments that examine the extent of hippocampal replay during sleep and how replay is affected in the absence of sleep. In Chapter 2, we found that the hippocampus reactivates neuronal patterns expressed during exploration of a novel environment for upto 10 hours in subsequent sleep with a half-maximum timescale of $~$6 …

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Are Neuronal Mechanisms Of Attentional Modulation Universal Across Human Sensory And Motor Brain Maps?, Edgar A. Deyoe, Wendy E. Huddleston, Adam S. Greenberg Jan 2022

Are Neuronal Mechanisms Of Attentional Modulation Universal Across Human Sensory And Motor Brain Maps?, Edgar A. Deyoe, Wendy E. Huddleston, Adam S. Greenberg

Kinesiology Faculty Articles

One's experience of shifting attention from the color to the smell to the act of picking a flower seems like a unitary process applied, at will, to one modality after another. Yet, the unique experience of sight vs smell vs movement might suggest that the neural mechanisms of attention have been selectively optimized to employ each modality to greatest advantage. Relevant experimental data can be difficult to compare across modalities due to design and methodological heterogeneity. Here we outline some of the issues related to this problem and suggest how experimental data can be obtained across modalities using more uniform …

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Interactions Among Sex, Apolipoprotein E Genotype, And 17-Beta Estradiol In A Mouse Model Of Alzheimer's Disease, Lisa Taxier Dec 2021

Interactions Among Sex, Apolipoprotein E Genotype, And 17-Beta Estradiol In A Mouse Model Of Alzheimer's Disease, Lisa Taxier

Theses and Dissertations

Alzheimer’s disease (AD) is the most common form of dementia, yet its cause remains a mystery and no truly effective treatments exist. The high incidence of AD, coupled with its devastating health and economic impacts, highlight the urgent need for continued research into the etiology of this disease (Ernst & Hay, 1994; Rice et al., 1993). Although existing and efficacious treatments for AD are lacking, several risk factors for AD have been identified. One such factor is apolipoprotein E genotype, which is the greatest genetic risk factor for AD (Ertekin-Taner, 2007; van der Flier et al., 2011). Another factor is …

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Effect Of Neighborhood Socioeconomic Disadvantage On Brain Functional Connectivity And Structural Properties In Trauma-Exposed Adults, Elisabeth Kathleen Webb Dec 2021

Effect Of Neighborhood Socioeconomic Disadvantage On Brain Functional Connectivity And Structural Properties In Trauma-Exposed Adults, Elisabeth Kathleen Webb

Theses and Dissertations

Though there has been substantial progress towards understanding brain-behavior relationships and characterizing the neurobiology of psychiatric disorders, research has not translated as expected into novel prevention and treatment of mental health conditions. One limitation may be the emphasis on individual-level variables (e.g., income) and omission of relevant area-level factors (e.g., neighborhood socioeconomic disadvantage). Recently, attention has been directed towards identifying the biological mechanisms by which neighborhoods impact mental health. The chronic stress associated with living in a disadvantaged neighborhood promotes a cascade of maladaptive events, which in turn impact brain structure and functioning. The processes affected by chronic neighborhood stressors …

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Resting State Functional Connectivity In The Default Mode Network: Relationships Between Cannabis Use, Gender, And Cognition In Adolescents And Young Adults, Megan Ritchay Aug 2021

Resting State Functional Connectivity In The Default Mode Network: Relationships Between Cannabis Use, Gender, And Cognition In Adolescents And Young Adults, Megan Ritchay

Theses and Dissertations

Introduction: Cannabis is the most commonly used illicit substance in the United States, and nearly 1 in 4 young adults are current cannabis users. The psychoactive component of cannabis, THC, is active at cannabinoid receptors, type 1, or CB1 receptors. CB1 receptors play a critical role in neural development, and chronic cannabis use causes desensitization and downregulation of these receptors. Chronic cannabis use is associated with changes in resting state functional connectivity (RSFC) in the default mode network (DMN) in adolescents and young adults, although results are somewhat inconsistent across studies, likely due to differing methodologies. Additionally, cannabis effects appear …

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Effects Of A Novel, Non-Toxic Histone Deacetylase Inhibitor On Hippocampal Memory Formation, Histone Acetylation, And Bdnf Gene Expression In Male Mice, Sarah Brianna Beamish Aug 2021

Effects Of A Novel, Non-Toxic Histone Deacetylase Inhibitor On Hippocampal Memory Formation, Histone Acetylation, And Bdnf Gene Expression In Male Mice, Sarah Brianna Beamish

Theses and Dissertations

Memory dysfunction is a common symptom of aging, neuropsychiatric disorders, and neurodegenerative disorders, yet truly effective treatments for memory loss do not exist. De novo gene transcription is a molecular requirement for long-term memory formation. The transcription of genes related to synaptic plasticity and learning are regulated in part by histone acetylation, an epigenetic mechanism that regulates chromatin accessibility. Pharmacological compounds that maintain histone acetylation, called histone deacetylase inhibitors (HDACi), enhance memory by preventing deacetylation of core histone proteins, which initiates binding of transcriptional machinery to open chromatin. Therefore, HDACi are potentially promising therapeutics that could be used to prevent …

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Resting-State Versus Breath-Hold For Testing Functional Magnetic Resonance Imaging Integrity In Pre-Surgical Planning, Nooshin Jafari Fesharaki Aug 2021

Resting-State Versus Breath-Hold For Testing Functional Magnetic Resonance Imaging Integrity In Pre-Surgical Planning, Nooshin Jafari Fesharaki

Theses and Dissertations

The neuro-vascular coupling mechanism responsible for blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) signals can be focally disrupted by various pathological factors (such as brain tumors) while leaving the underlying neurons functionally intact. Such neuro-vascular uncoupling (NVU) can pose serious complications for clinical use of fMRI. Mapping of cerebrovascular reactivity (CVR), which is a measure of the dilatory function of cerebral vasculature, can be a useful approach for detecting potential NVU. The widely-accepted approach for non-invasive CVR mapping requires the patient to perform a breath-hold challenge, which may have practical disadvantages for many patient populations. Thus, a …

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Neural Substrates Of Fear Generalization And Its Associations With Anxiety And Intolerance Of Uncertainty, Ashley Ann Huggins Aug 2021

Neural Substrates Of Fear Generalization And Its Associations With Anxiety And Intolerance Of Uncertainty, Ashley Ann Huggins

Theses and Dissertations

Fear generalization - the tendency to interpret ambiguous stimuli as threatening due to perceptual similarity to a learned threat – is an adaptive process. Overgeneralization, however, is maladaptive and has been implicated in a number of anxiety disorders. Neuroimaging research has indicated several regions sensitive to effects of generalization, including regions involved in fear excitation (e.g., amygdala, insula) and inhibition (e.g., ventromedial prefrontal cortex). Research has suggested several other small brain regions may play an important role in this process (e.g., hippocampal subfields, bed nucleus of the stria terminalis [BNST], habenula), but, to date, these regions have not been examined …

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Behavioral And Neural Correlates Of Episodic Memory Regulation, Mrinmayi Kulkarni Aug 2021

Behavioral And Neural Correlates Of Episodic Memory Regulation, Mrinmayi Kulkarni

Theses and Dissertations

Episodic memory retrieval, while critical for daily living, needs to be regulated to maintain goal-directed behavior. Past work has shown that episodic memory regulation engages brain regions involved in cognitive control, such as the dorsolateral and ventrolateral prefrontal cortex. These regions interact with the medial temporal lobe structures to control retrieval processes. In the current study, I paired eye-tracking, a sensitive index of memory, with fMRI in a novel paradigm to address several open questions in the field of episodic memory regulation. Participants initially encoded three celebrity faces and three tools with multiple indoor and outdoor scenes. In a subsequent …

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Longitudinal Changes In Resting-State Functional Connectivity Of The Salience Network Among Individuals At-Risk For Ptsd Development, Kyrie Sellnow May 2021

Longitudinal Changes In Resting-State Functional Connectivity Of The Salience Network Among Individuals At-Risk For Ptsd Development, Kyrie Sellnow

Theses and Dissertations

Predicting post-traumatic stress disorder (PTSD) following a traumatic event has been a focus of recent neuroimaging research in the hopes of identifying key biomarkers that contribute to the disorder’s development. One possibility relies on understanding the connectivity between intrinsic connectivity networks (ICNs), including the salience network (SN). Prior research has consistently identified hyperconnectivity among SN regions among those with chronic PTSD, and this study aimed to examine the role of SN connectivity over time on PTSD symptom development. To do so, this study recruited individuals presenting to the Emergency Department with traumatic injuries to complete two resting-state fMRI scans: one …

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Behavioral, Physiological, And Molecular Characterization Of Long-Term Administration Of A Novel Estrogen Receptor Beta Agonist In A Mouse Model Of Menopause, Aaron William Fleischer May 2021

Behavioral, Physiological, And Molecular Characterization Of Long-Term Administration Of A Novel Estrogen Receptor Beta Agonist In A Mouse Model Of Menopause, Aaron William Fleischer

Theses and Dissertations

The menopausal loss of circulating hormones, including estrogens, is associated with negative symptoms, such as hot flashes, anxiety and depression, cognitive decline, and weight gain. Although estrogenic hormone therapies (HT) prevent many of the negative symptoms related to the menopausal transition, these same therapies are associated with increased health risks, such as the development of breast and ovarian cancers, which is mediated by the activation of the a (ERa), but not b (ERb), estrogen receptor isoform. Furthermore, ERb agonism has previously been shown to reduce preclinical indices of hot flashes, memory decline, anxiety, and depression. As most ERb agonists are …

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Functional Responding To Appetitive Faces Among Cannabis-Using Adolescents And Young Adults, Ryan Michael Sullivan May 2021

Functional Responding To Appetitive Faces Among Cannabis-Using Adolescents And Young Adults, Ryan Michael Sullivan

Theses and Dissertations

Cannabis use is associated with attenuated reward signaling, yet few studies have examined this relationship when viewing rewarding appetitive faces while undergoing functional neuroimaging. Furthermore, few neuroimaging analyses have examined the moderating role of gender on task-based fMRI outcomes. This study explored functional BOLD response elicited by appetitive faces while engaged in an affective go/no-go task, and specifically investigated the differences between cannabis-using and control groups, whether gender moderate findings, and brain-behavior associations. Participants (ages 16-26 years) were scanned after at least 3-weeks of monitored abstinence (cannabis-using group = 35; control group = 33). The findings demonstrated aberrant activation in …

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Neural Correlates Underlying The Interactions Between Anxiety And Cannabis Use In Predicting Motor Response Inhibition, Richard Ward May 2021

Neural Correlates Underlying The Interactions Between Anxiety And Cannabis Use In Predicting Motor Response Inhibition, Richard Ward

Theses and Dissertations

The ability to effectively withhold an inappropriate response is a critical feature of cognitive control. Prior research indicates alterations in neural processes required for motor response inhibition in anxious individuals, including those with posttraumatic stress disorder (PTSD), and those who engage in regular cannabis use. However, thus far most research has examined how anxiety-related symptoms and cannabis use influence response inhibition in isolation of one another. The current study examined the interactions between anxious symptomology and recent cannabis use in a sample that recently experienced a traumatic event using functional magnetic resonance imaging (fMRI) during the completion of a Stop-Signal …

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Sex- And Age-Associated Effects On The Retrosplenial Cortex Following Trace Fear Learning, Hanna Yousuf May 2021

Sex- And Age-Associated Effects On The Retrosplenial Cortex Following Trace Fear Learning, Hanna Yousuf

Theses and Dissertations

The rodent granular retrosplenial cortex (gRSC) forms reciprocal connections with the thalamus and hippocampus (Van Groen and Wyss, 1990, 1992; Sugar et al., 2011). The gRSC is well-positioned to coordinate information between higher-order brain structures to support complex forms of memory such as associative trace fear memories (Kwapis et al., 2014, 2015). Further, sex differences in fear learning and mechanisms underlying fear memories are observed in many of the brain regions implicated in trace fear learning such as the hippocampus, amygdala, and mPFC (Maren et al., 1994; Dalla et al., 2009; Gresack et al., 2009; Blume et al., 2017; Keiser …

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Restorative Potential And Working Memory Capacity Of Exposure To Vegetation In Indoor Built Environments, Jee Heon Rhee Dec 2020

Restorative Potential And Working Memory Capacity Of Exposure To Vegetation In Indoor Built Environments, Jee Heon Rhee

Theses and Dissertations

This research seeks to understand how natural elements – specifically, vegetation in the indoor environment - influence people’s ability to restore attention and working memory capacity. Previous research demonstrates the benefits of nature on human beings in various ways. For instance, numerous studies show the positive effects of nature on stress reduction (Hartig, Mang, & Evans, 1991; Ulrich et al., 1991) and attention restoration (Staats, Kieviet, & Hartig, 2003). However, most of these studies focus on the effect of nature in outdoor settings. Relatively few studies focus on the presence of natural elements indoors. This is an important gap in …

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Inactivation Of Nucleus Reuniens Impairs Spatial Memory In Mice, Miranda Schwabe Dec 2020

Inactivation Of Nucleus Reuniens Impairs Spatial Memory In Mice, Miranda Schwabe

Theses and Dissertations

Episodic memory is a complex process requiring input from several regions of the brain. Coordinated activity in the Dorsal Hippocampus (DH) and medial Prefrontal Cortex (mPFC) is required for episodic memory consolidation. Our laboratory demonstrated that simultaneous subthreshold chemogenetic inactivation of the dorsal hippocampus (DH) and medial prefrontal cortex (mPFC) impairs the consolidation of object placement (OP) and object recognition (OR) memory in female mice (Tuscher et al., 2018), suggesting that these two brain regions work in concert to promote memory consolidation. However, the mechanisms through which the DH and mPFC interact to promote memory consolidation remain poorly understood. A …

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The Role Of Cerebellar Structural Plasticity And Astrocytic Activity In Motor-Skill Learning, Morgan Stevenson Dec 2020

The Role Of Cerebellar Structural Plasticity And Astrocytic Activity In Motor-Skill Learning, Morgan Stevenson

Theses and Dissertations

Motor-skill learning is associated with cerebellar synaptogenesis and astrocytic hypertrophy, but most of these assessments of cerebellar ultrastructure have been completed after one month of training. After one month of training, the motor-skills necessary to complete these tasks have been acquired for weeks. Furthermore, the contributions of cerebellar astrocytes to motor-skill learning remains largely unexamined. The first experiment of this dissertation aimed to characterize cerebellar ultrastructure during the acquisition phase of motor-skill learning, at a point when motor performance is still improving. The second experiment aimed to examine the contributions of cerebellar astrocytes to motor-skill learning by activating astrocytic Gi-signaling …

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Data-Driven Approach To Dynamic Resting State Functional Connectivity In Post-Traumatic Stress Disorder, Carissa Weis Dec 2020

Data-Driven Approach To Dynamic Resting State Functional Connectivity In Post-Traumatic Stress Disorder, Carissa Weis

Theses and Dissertations

Posttraumatic stress disorder (PTSD) is a heterogenous psychological disorder that may result from exposure to a traumatic event. Using functional magnetic resonance imaging (fMRI), symptoms of PTSD have been associated with aberrations in brain networks that emerge in the absence of a given cognitive demand or task, called resting state networks. Most previous research in resting state networks and PTSD has focused on aberrations in the static functional connectivity among specific regions of interest (ROI) in the brain and within canonical networks constrained by a priori hypotheses. However, dynamic fMRI, an approach that examines changes in brain network characteristics over …

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The Impact Of Task Load On Neural Entrainment To Attended Speech: A Dual-Task Magnetoencephalography (Meg) Paradigm, Michelle Tamar Kassel Aug 2020

The Impact Of Task Load On Neural Entrainment To Attended Speech: A Dual-Task Magnetoencephalography (Meg) Paradigm, Michelle Tamar Kassel

Theses and Dissertations

Speech comprehension in a noisy environment requires active cognitive control mechanisms to select the relevant speech signal while filtering out irrelevant distractions. When processing speech in a multitask scenario, neural resources underlying cognitive control are considerably burdened and interfering information becomes more difficult to ignore. The present study utilized magnetoencephalography (MEG) to investigate the impact of multitasking on selective attention to speech. Twenty healthy adults performed a multitask paradigm with varying levels of both competing auditory distraction and concurrent visual working memory load. While increased visual working memory load was associated with reduced selective attention to speech in both the …

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The Association Of Aerobic Fitness With Resting State Functional Connectivity And Verbal Learning And Memory In Healthy Young Adults, Kyle Joseph Jennette Aug 2020

The Association Of Aerobic Fitness With Resting State Functional Connectivity And Verbal Learning And Memory In Healthy Young Adults, Kyle Joseph Jennette

Theses and Dissertations

The beneficial effects of exercise and cardiopulmonary fitness on general health, quality of life, and reduction of mortality are well known in older adults. There is evidence to support the positive effects of exercise and aerobic fitness on psychiatric and neurocognitive function in children, adults, and older adults. Indeed, many studies have explored the positive effects of aerobic fitness on slowing cognitive decline associated with normal and pathological aging. However, comparatively fewer empirical studies in the literature exist to support and understand the effects of aerobic fitness on the developing brain, particularly during adolescence and young adulthood, especially as it …

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Molecular And Physiological Plasticity In The Ventral Hippocampus Following Associative Fear Learning, Vanessa Ehlers Aug 2020

Molecular And Physiological Plasticity In The Ventral Hippocampus Following Associative Fear Learning, Vanessa Ehlers

Theses and Dissertations

Pavlovian fear conditioning is useful for understanding how various brain regions support associative fear memory. The hippocampus plays an especially important role in fear learning. Evidence suggests disrupted dorsal and/or ventral hippocampal activity leads to pronounced fear memory deficits, and the dorsal hippocampus displays distinct plasticity changes following fear learning, including altered intrinsic excitability and immediate early gene expression. These mechanisms support fear memory consolidation. However, the molecular and physiological plasticity of the ventral hippocampus following various forms of fear learning remains poorly understood. The current experiments examine the nature of associative fear learning-related plastic changes in the ventral hippocampus …

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Shaped By The Environment: The Influence Of Childhood Trauma Exposure, Individual Socioeconomic Position, And Neighborhood Disadvantage On Brain Morphology, Elisabeth Kathleen Webb Aug 2020

Shaped By The Environment: The Influence Of Childhood Trauma Exposure, Individual Socioeconomic Position, And Neighborhood Disadvantage On Brain Morphology, Elisabeth Kathleen Webb

Theses and Dissertations

The relationship between an individual’s socioeconomic position (SEP) and their overall physical and mental health has been well demonstrated. Far less is known about how area-level factors, such as neighborhood disadvantage, “get under the skin”. Previous research indicates lower SEP and childhood trauma negatively effects brain structure and function. The hippocampus, amygdala, and ventromedial prefrontal cortex (vmPFC) are particularly vulnerable to adversity. The current study investigated how individual SEP, childhood trauma, and neighborhood disadvantage impact these structures. Two-hundred and fifteen individuals were recruited from an Emergency Department in southeastern Wisconsin. Two-weeks post-traumatic injury, participants completed a structural magnetic resonance imaging …

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Optogenetic Interrogation Of Hippocampal Circuit Stabilization, Laurel Watkins De Jong Aug 2020

Optogenetic Interrogation Of Hippocampal Circuit Stabilization, Laurel Watkins De Jong

Theses and Dissertations

Understanding the response of excitatory and inhibitory populations to varying input is vital to understanding how a brain region transforms information. Optogenetics - the combined use of optics and genetics to control the activity of proteins, provides neuroscientists with a tool to interrogate neuronal circuits with high spatio-temporal resolution and targeted cell specificity. This thesis examines the effects of optogenetic manipulations on hippocampal circuit responses. The hippocampus is a structure required for the formation and retention of episodic memories and is comprised of anatomically distinct subregions including cornu ammonis 3 (CA3) and cornu ammonis 1 (CA1). Both regions, despite differences …

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Attention Capture By Episodic Long-Term Memories: Evidence From Eye Movement Data, Allison Eleanor Nickel May 2020

Attention Capture By Episodic Long-Term Memories: Evidence From Eye Movement Data, Allison Eleanor Nickel

Theses and Dissertations

Successfully navigating the world on a moment-to-moment basis requires the interaction of multiple cognitive processes. Therefore, studies that examine when and how these fundamental processes interact can provide important insights into how we behave. Many studies indicate that long-term memory can facilitate search for a target object (e.g., contextual cueing), however, the ways in which long-term memory might capture attention and disrupt goal-directed behavior have not been well studied. In five experiments, questions about whether encoded objects might capture attention, even when they are task-irrelevant, were addressed. Each experiment began with an encoding phase, where participants were instructed to commit …

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Neural Substrates Of Active Avoidance And Its Impact On Fear Extinction, Elizabeth Parisi May 2020

Neural Substrates Of Active Avoidance And Its Impact On Fear Extinction, Elizabeth Parisi

Theses and Dissertations

Models of anxiety suggest that avoidance of a conditioned fear stimulus prevents new safety learning, thereby serving to maintain fear. However, there is little empirical data in humans on the impact of avoidance of conditioned fear stimuli on subsequent fear extinction. In the present study I investigated the effect of avoidance of threat on neural activity during avoidance/control and a subsequent extinction phase using ultra high-resolution (7T) fMRI. Results indicated that active avoidance was associated with increased activity in regions involved in reward prediction, but this did not differentiate active avoidance from an active control condition. Neural activation during the …

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