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Full-Text Articles in Neuroscience and Neurobiology

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 …


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 …


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 …


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 …


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 …


Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus May 2019

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …


Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus May 2019

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …


Auditory And Contextual Contributions To Memory Lability And Synaptic Destabilization In The Amygdala, Nicole Christine Ferrara Aug 2018

Auditory And Contextual Contributions To Memory Lability And Synaptic Destabilization In The Amygdala, Nicole Christine Ferrara

Theses and Dissertations

Pavlovian fear conditioning provides a way to investigate memory formation and retrieval. During fear conditioning, a conditional stimulus (CS) is paired with an aversive outcome and the CS acquires aversive value over several pairings. The CS may then be presented during a retrieval session where fear responding is measured as an indicator of memory strength. Retrieval sessions may allow for the incorporation of new information into the original memory trace by destabilizing amygdala synapses. However, the specific circuits and neural inputs that contribute to memory lability and synaptic destabilization during a retrieval session are poorly understood. Previous work has shown …


The Role Of Brain-Synthesized E2 In Hippocampal Learning And Memory Consolidation In Female Mice, Jennifer Tuscher Dec 2014

The Role Of Brain-Synthesized E2 In Hippocampal Learning And Memory Consolidation In Female Mice, Jennifer Tuscher

Theses and Dissertations

The potent estrogen 17beta-Estradiol (E2) plays a critical role in neuroprotection, serving as an important trophic factor for neurons in the hippocampus, basal forebrain, and prefrontal cortex (Brinton, 2001). In the hippocampus, E2 promotes neurogenesis (Tanapat et al., 1999, Prange-Kiel et al., 2006), protects against cell death after ischemic injury (Garcia-Segura et al., 2001, Zhao and Brinton, 2007), and helps maintain spine morphology crucial for synaptic connectivity and memory (Woolley et al., 1990; Gould et al., 1990, Woolley and McEwen, 1992, Li et al., 2004). However, the mechanisms through which E2 promotes synaptic plasticity and enhances memory function are largely …


The Hippocampus And Adult Neurogenesis: A Neural Circuit With A Common Role In Behavioral Flexibility And Detailed Memory, Brian Pochinski Dec 2014

The Hippocampus And Adult Neurogenesis: A Neural Circuit With A Common Role In Behavioral Flexibility And Detailed Memory, Brian Pochinski

Theses and Dissertations

Work with patient H.M. sparked great interest in the role of the hippocampus in learning and memory. Later, the findings that new neurons are born in the adult dentate gyrus (DG) and that they become functionally integrated in neural circuits created new excitement in the field of learning and memory. While there is ample evidence that the hippocampus and adult neurogenesis are involved in learning and memory, similar inconsistencies in both areas have clouded interpretations of their precise role. We propose that studying the role of hippocampus and neurogenesis in the DG must be merged into a more cohesive field …


Neurophysiological And Morphological Plasticity In Rat Hippocampus And Medial Prefrontal Cortex Following Trace Fear Conditioning, Chenghui Song Aug 2014

Neurophysiological And Morphological Plasticity In Rat Hippocampus And Medial Prefrontal Cortex Following Trace Fear Conditioning, Chenghui Song

Theses and Dissertations

Pavlovian fear conditioning provides a useful model system for investigating the mechanisms underlying associative learning. In recent years, there has been an increasing interest in "trace" fear conditioning, which requires conscious awareness of the contingency of CS and US therefore considered as a rodent model of explicit fear. Acquisition of trace fear conditioning requires an intact hippocampus and medial prefrontal cortex (mPFC), but the underlying mechanisms are still unclear. The current set of studies investigated how trace fear conditioning affects neuronal plasticity in both hippocampus and mPFC in adult rats. Trace fear conditioning significantly enhanced both intrinsic excitability and synaptic …