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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
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 …
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
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 …
Molecular And Physiological Plasticity In The Ventral Hippocampus Following Associative Fear Learning, Vanessa Ehlers
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 …
Attention Capture By Episodic Long-Term Memories: Evidence From Eye Movement Data, Allison Eleanor Nickel
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 …
Neural Correlates Of Memory Decisions Made In The Face Of Conflict, Elaine Mahoney
Neural Correlates Of Memory Decisions Made In The Face Of Conflict, Elaine Mahoney
Theses and Dissertations
We’ve all experienced moments where, for some reason or another, we don’t want to reveal to others what we truly know. The current experiment investigated questions about the behavioral and neural correlates of these types of memory decisions made in the face of a conflicting goal. Participants in this experiment studied several scene-face pairs and were tested with three-face displays preceded by studied scene cues. They were instructed to indicate whether the three-face display contained the matching associate or not. Critically, half of the participants were instructed to simulate feigned memory impairment (i.e. simulators), while the remainder were instructed to …
Rescuing Age-Related Proteolysis Deficits With Methylene Blue, Shane E. Pullins
Rescuing Age-Related Proteolysis Deficits With Methylene Blue, Shane E. Pullins
Theses and Dissertations
The average lifespan is constantly increasing with the advent of new medical techniques, and age-related cognitive decline is becoming a prevalent societal issue. Even during healthy aging, humans and rats exhibit progressive deficits in episodic/declarative memory. In laboratory rats, age-related memory impairment can be assessed with trace fear conditioning (TFC). Recent research implicates ubiquitin proteasome system-mediated protein degradation in the synaptic plasticity supporting memory formation and retrieval. In rats, aging leads to decreased basal proteolytic activity in brain structures known to support the acquisition and retrieval of trace fear memories, and our preliminary data suggests activity-dependent proteasome activity declines in …
The Effects Of The Hiv-1 Tat Protein And Morphine On The Structure And Function Of The Hippocampal Ca1 Subfield, William D. Marks
The Effects Of The Hiv-1 Tat Protein And Morphine On The Structure And Function Of The Hippocampal Ca1 Subfield, William D. Marks
Theses and Dissertations
HIV is capable of causing a set of neurological diseases collectively termed the HIV Associated Neurocognitive Disorders (HAND). Worsening pathology is observed in HIV+ individuals who use opioid drugs. Memory problems are often observed in HAND, implicating HIV pathology in the hippocampus, and are also known to be exacerbated by morphine use. HIV-1 Tat was demonstrated to reduce spatial memory performance in multiple tasks, and individual subsets of CA1 interneurons were found to be selectively vulnerable to the effects of Tat, notably nNOS+/NPY- interneurons of the pyramidal layer and stratum radiatum, PV+ neurons of the pyramidal layer, and SST+ neurons …
The Mechanisms Underlying Cocaine-Induced Overexpression Of Basic Fibroblast Growth Factor (Bfgf, Fgf2), An Effect Reversed By Extinction, Madalyn Hafenbreidel
The Mechanisms Underlying Cocaine-Induced Overexpression Of Basic Fibroblast Growth Factor (Bfgf, Fgf2), An Effect Reversed By Extinction, Madalyn Hafenbreidel
Theses and Dissertations
Drug addiction is characterized by compulsive drug use and chronic relapse despite negative consequences. Drug-induced structural and functional changes in the brain are thought to underlie these characteristics. One mechanism that may mediate these characteristics are growth factors, such as basic fibroblast growth factor (bFGF or FGF2), as they are necessary for cellular growth, survival, differentiation, and have roles in memory, mood, and anxiety disorders. bFGF mRNA and protein expression is increased following stimulant administration and is necessary for stimulant-induced changes in dendrites and behavioral sensitization. Moreover, addiction is maintained by cues associated with the drug, as they can can …
Eye Movement Effects In Simulated Object Recognition Memory Impairment, Dmitriy Kazakov
Eye Movement Effects In Simulated Object Recognition Memory Impairment, Dmitriy Kazakov
Theses and Dissertations
Malingering is the purposeful fabrication of symptoms for secondary gain. Memory problems are the most reported symptom, and object recognition tests are often used in clinical settings to evaluate these claims. Past research has shown that eye movements can indirectly index memory, in that greater viewing is directed at studied stimuli 500-750 ms after display onset. The present study evaluated eye movements as a potential method of detecting feigned memory impairment. Forty-eight participants, half simulators, studied standardized images and took a memory test. Several levels of analysis were used to detect broad trends and brief effects. Simulators performed significantly worse …
Regulation Of Mtor And Erk Signaling In The Amygdala Through Proteolytic Modulation Of Pp2a Activity Following Auditory Fear Learning, David Sylvan Reis
Regulation Of Mtor And Erk Signaling In The Amygdala Through Proteolytic Modulation Of Pp2a Activity Following Auditory Fear Learning, David Sylvan Reis
Theses and Dissertations
The consolidation of fear memories is known to depend on a number of critical cellular processes including de novo protein synthesis and 26S proteasome-dependent protein degradation following auditory fear conditioning (Jarome et al., 2011; Kwapis et al., 2011). Early work has suggested that protein degradation, mediated by the ubiquitin proteasome system (UPS), may regulate the requirement for de novo protein synthesis during memory consolidation (Jarome & Helmstetter, 2014). However, the precise way in which the UPS is able to regulate mechanisms of protein synthesis remain unclear. In the present set of experiments, we investigated the role of the protein phosphatase …
The Hippocampus And Adult Neurogenesis: A Neural Circuit With A Common Role In Behavioral Flexibility And Detailed Memory, Brian Pochinski
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 …
Memory Retrieval Is Maintained By Intrinsic And Synaptic Plasticity In Prelimbic Cortex, James Otis
Memory Retrieval Is Maintained By Intrinsic And Synaptic Plasticity In Prelimbic Cortex, James Otis
Theses and Dissertations
Abnormally strong memories underlie common disorders including addiction and post-traumatic stress disorder (PTSD). Memory disruption would therefore be beneficial for treatment of these disorders. Evidence reveals that cocaine conditioned place preference (CPP) memories are susceptible to long-lasting disruption during memory retrieval. For example, inhibition of β-adrenergic receptor (β-AR) activity within the prelimbic medial prefrontal cortex (PL-mPFC) prevents cocaine CPP memory retrieval, and this retrieval impairment is both long-lasting and prevents subsequent reinstatement of the CPP. Despite this, whether PL-mPFC β-AR activity is a fundamental mechanism required to maintain retrieval of other memories is unclear. Furthermore, how PL-mPFC β-AR activity maintains …
Is Contextual Cue Learning Flexible? An Eye-Movement Study Of The Contextual Cueing Task, Youcai Yang
Is Contextual Cue Learning Flexible? An Eye-Movement Study Of The Contextual Cueing Task, Youcai Yang
Theses and Dissertations
Visual searching can be facilitated without awareness when the target is repeatedly presented in an invariant context in tasks such as contextual cueing (Chun & Jiang 1998). A behavioral cost (increased reaction time) was observed when the target was moved to a new location but no such cost was observed when the target returned to the initial location. The lack of cost for return suggests two possible explanations: One is that the learning can update the initial learning to acquire both target locations, which suggests the implicit learning is flexible. The other is that the contextual cue leaning cannot update …
The Role Of A Camkii/Pka-Protein Degradation-Glur2 Pathway In The Control Of Memory Updating Following Retrieval, Timothy Jarome
The Role Of A Camkii/Pka-Protein Degradation-Glur2 Pathway In The Control Of Memory Updating Following Retrieval, Timothy Jarome
Theses and Dissertations
Reconsolidation is thought to be a process whereby consolidated memories can be modified following retrieval. However, very little is known about the molecular mechanisms that regulate this reconsolidation process. In the present series of experiments we tested if memories "destabilize" or become labile following retrieval through a specific signaling pathway. We found that retrieval of a contextual fear memory differentially increased proteasome activity in the amygdala and hippocampus and resulted in unique changes in AMPA receptor subunit expression in these brain regions. These changes were dependent on CaMKII activity, which was required for increases in Rpt6-S120 phosphorylation, proteasome activity and …