Life Sciences Commons^™

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 …

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 …

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 …

Changes In Resting-State Functional Connectivity Following Delay And Trace Fear Conditioning Acquisition And Extinction, Douglas Hank Schultz

Theses and Dissertations

Consolidation is the process of stabilizing a recently acquired memory into a more permanent or durable form. Several studies with laboratory animals have uncovered valuable information about the process of consolidation, but less is known about the process of consolidation in healthy humans. The current study examined the consolidation of emotional memories in different brain circuits in healthy humans using resting-state fMRI. We used the acquisition and extinction of two variations of Pavlovian fear conditioning, delay and trace, which rely on slightly different circuits to examine changes in functional connectivity related to a general fear learning process and also to …

Impact Of Faah Genotype And Marijuana Use On Brain Structure And Neuropsychological Performance In Emerging Adults, Skyler Gabriel Shollenbarger

Theses and Dissertations

Introduction: Chronic MJ use may be associated with higher cognitive ability impairments (see Lisdahl et al., 2013). Regions undergoing later maturation (Gogtay 2004), may be at increased risk for MJ-induced alterations. Endogenous cannabinoid signaling (ECS) is modulated by the function the enzyme Fatty Acid Amide Hydrolase (see Ho & Hilard, 2005), thus the gene encoding for this enzyme (FAAH) impacts ECS (Sipe et al., 2002). Here, we examine the impact of MJ use and FAAH genotype on PFC complexity and underlying frontal white matter (WM) integrity in young adults. Methods: Participants included 37 MJ users and 37 non-using young adults …

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 …

Neural Responses During Trace Conditioning With Face And Non-Face Stimuli Recorded With Magnetoencephalography, Nicholas Lee Balderston

Theses and Dissertations

During fear conditioning a subject is presented with an initially innocuous stimulus like an image (conditioned stimulus; CS) that predicts an aversive outcome like a mild electric shock (unconditioned stimulus; UCS). Subjects rapidly learn that the CS predicts the UCS, and show autonomic fear responses (CRs) during the presentation of the CS. When the CS and the UCS coterminate, as is the case for delay conditioning, individuals can acquire CRs even if they are unable to predict the occurrence of the UCS. However when there is a temporal gap between the CS and the UCS, CR expression is typically dependent …

The Role Of The Amygdala, Retrosplenial Cortex, And Medial Prefrontal Cortex In Trace Fear Extinction And Reconsolidation, Janine Lynn Kwapis

Theses and Dissertations

A wealth of research has outlined the neural circuits responsible for the consolidation, reconsolidation, and extinction of standard "delay" fear conditioning, in which awareness is not required for learning. Far less is understood about the neural circuit supporting more complex, explicit associations. "Trace" fear conditioning is considered to be a rodent model of explicit fear because it relies on the cortex and hippocampus and requires explicit contingency awareness in humans for successful acquisition. In the current set of studies, we aimed to better characterize the neural circuit supporting the consolidation, reconsolidation, and extinction of trace fear in order to better …

Metergoline, The Basolateral Amygdala And The Ventral Pallidum: Implications For Panic Disorder, Douglas Ryan Schuweiler

Theses and Dissertations

Panic disorder (PD) is a common mental illness characterized by recurring spontaneous panic attacks. Scientific investigation into PD has been accelerated by the development of rat models of PD. These models can be validated by responses to intravenous sodium lactate (NaLac), including tachycardia, that are similar to PD patient responses. Previous work on established PD models has suggested that antagonism of serotonin (5-HT) receptors in the basolateral amygdala (BLA) may be sufficient to model PD. To test this hypothesis metergoline (MET), a 5-HT receptor antagonist, or vehicle was microinjected into the BLA of anesthetized rats. Following the microinjection, NaLac or …

Exercise-Induced Hypoxia, Angiogenesis, And Behavioral Flexibility In The Adult Rat, Kiersten Lee Berggren

Theses and Dissertations

Exercise induces a myriad of effects on the brain from the growth of new capillaries and neurons, to improvements in cognitive performance. Additionally, recent research has shown that commencement of an exercise regimen also causes apoptosis. Therefore, it is possible that exercise-induced increases in oxygen demand cause the brain to transiently experience a state of hypoxia. To investigate this hypothesis, we measured protein levels of hypoxia inducible factor 1 alpha (HIF-1α), a transcription factor known to be upregulated in conditions of hypoxia or ischemia, in animals exposed to a single bout of treadmill exercise. After exercise animals were sacrificed at …

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 …

Dissociation Of Β1 And Β2 Adrenergic Receptor Subtypes In Retrieval And Reconsolidation Of A Cocaine Conditioned Place Preference, Michael Fitzgerald

Theses and Dissertations

Drug-seeking behavior is maintained by encounters with drug-associated cues, and disrupting retrieval or reconsolidation of the drug-cue associations could reduce the risk of relapse. Previous work has shown beta-adrenergic receptor (beta-AR) antagonists can prevent retrieval or reconsolidation of a cocaine conditioned place preference (CPP) when administered either before or after test, respectively (Otis and Mueller, 2011; Otis et al., 2013). However, the specific beta-AR subtypes that mediate retrieval and reconsolidation of a cocaine CPP remain unknown. Here we used selective blockade of & beta-1 or beta-2-AR subtypes to determine the effects on retrieval and reconsolidation of a cocaine CPP. During …

Immediate Early Gene Expression In Medial Prefrontal Cortex And Hippocampus As A Function Of Aging, Megha Sehgal

Theses and Dissertations

Normal aging is accompanied by cognitive decline that differs from other aging-related pathological states like Alzheimer's disease. With an increasing proportion of the world population falling in an age group of 65 years and above, a preventive gerontological approach would improve the quality of life in the elderly. Especially important in this regard is the early detection of cognitive decline, so that appropriate measures can be taken to prevent development of cognitive deficits. Impairment in cognitive flexibility, the ability to modify a previously learnt behavior, is one such measure of impairment across species in aged animals. Previous work from our …

The Role Of Nmda Receptors In Extinction Of Cocaine Self-Administration, Madalyn Hafenbreidel

Theses and Dissertations

Relapse is highly prevalent among recovering addicts, and can be triggered by associations made between the rewarding effects of the drug and cues, such as drug paraphernalia or contexts. Inhibiting these associations, through new extinction learning, could help reduce relapse rates. Extinction is formed in phases, like other types of memory. The memory first is acquired in short-term memory, then is consolidated into long-term storage from which it can be retrieved at a later time (Quirk & Mueller, 2008). NMDA receptors are necessary for extinction in other paradigms (Santini, Muller, & Quirk, 2001), and we previously found that blocking NMDA …

Behavior Change In Applied Sport Psychology: The Use Of Processes Of Change In Psychological Training For Athletes, William Vincent Massey

Theses and Dissertations

The results of previous research (e.g. Leffingwell, Rider, & Williams, 2001; Massey, Meyer, & Hatch, 2011; Zizzi & Perna, 2003) have led scholars to conclude that the Transtheoretical Model (TTM) may be an appropriate paradigm to study readiness to change in sport psychology settings. However, processes of change - a critical element to the TTM - have yet to be studied or measured in an athlete population. As such, the purpose of the current investigation was to initially develop and examine a measure of the processes of change for use in applied sport psychology settings. Informed by relevant literature, an …

Investigation Of Web-Based Motivational Interviewing To Increase Physical Activity Participation Among Adults, Sasha Karnes

Theses and Dissertations

Interventions to enhance physical activity (PA) participation are needed given the high prevalence of under-activity and inactivity (CDC, 2001) and related occurrence of negative health consequences among the general adult population (Kung, Hoyert, Xu, & Murphy, 2008). Preliminary support for a therapeutic technique called Motivational Interviewing (MI) suggests promise for application to enhance PA participation (Burke, Arkowitz, & Menchola, 2003). Given the need for interventions to enhance PA and the preliminary support for MI as an intervention to increase PA, the aims of the current study were to: (a) determine if web-based MI is effective in enhancing PA participation, and …

Motivating Healthy Diet Behaviors: The Self-As-Doer Identity, Amanda Brouwer

Theses and Dissertations

Background: Self-identity predicts healthy eating behaviors and intentions above and beyond Theory of Planned Behavior components (TPB; i.e., attitudes, perceived behavioral control, and subjective norms), but interventions exploring the relationship between self-identity and motivation are limited. Self-as-doer identity may be an important point of intervention for healthy eating behaviors (Houser-Marko & Sheldon, 2006). Therefore, I investigated whether the experimental manipulation of a self-as-doer identity predicted improved healthy food consumption, intentions, and increased self-identity as a healthy eater compared to women who received nutritional education or no intervention directly following the intervention and one month post-intervention.

Method: Participants were 79 women …

Relationship Between Counter Movement Jump Performance And Extraversion Level, David James Cornell

Theses and Dissertations

Introduction: Sport psychology literature has demonstrated a relationship between personality and physical ability and athletic performance. In general, individuals who exhibit a greater degree of extraversion display a greater physical ability and athletic performance than individuals who exhibit a lower degree of extraversion. The physiology literature has also demonstrated relationships between extraversion level and movement time and electrophysiological mechanisms (i.e., muscle activity) during a fine movement task. However to date, no study has investigated if these physiological relationships manifest themselves during a gross movement task. If a relationship exists, it may provide mechanistic reasoning behind the previously observed relationships between …

The Level And Determinants Of Burnout Of Mormon Mothers In A Utah Suburban Town, Christina Mordock

Theses and Dissertations

The purpose of this study was to examine burnout in Mormon mothers in a suburban Utah town. Specifically the amount and some determinants of burnout among these Mormon women was studied. A random sample of 266 Mormon mothers completed a questionnaire and a modified version of the Maslach Burnout Inventory (MBI) which consisted of three subscales, (Emotional Exhaustion, Depersonalization, and Personal Accomplishment), and two categories in each subscale (Frequency and Intensity). The subjects scored in the moderately burned out category in each subscale. Significant relationships were found between the amount of burnout and the following: the age of the mother, …

Assessment Of Influence That The Church Of Jesus Christ Of Latter-Day Saints Has On Exercise Habit Of Members Living In Utah County, Gary L. Preston

Theses and Dissertations

This study identified and analyzed the influence the Church of Jesus Christ of Latter-day Saints had on the decision of 309 respondents to exercise. The data obtained from the questionaires were analyzed using chi-square to compare males and females. Within the limitations of this study, the following conclusions were justified: women were more influenced by the LDS Church to exercise than men; LDS males and females exercised more than average American adults; walking, jogging, and aerobic dance were the most popular choices of LDS exercisers; and, there is a need to improve the awareness of LDS members concerning the Physical …