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Accelerated Forgetting In People With Epilepsy: Pathologic Memory Loss, Its Neural Basis, And Potential Therapies, Sarah Ashley Steimel Phd

Dartmouth College Ph.D Dissertations

While forgetting is vital to human functioning, delineating between normative and disordered forgetting can become incredibly complex. This thesis characterizes a pathologic form of forgetting in epilepsy, identifies a neural basis, and investigates the potential of stimulation as a therapeutic tool. Chapter 2 presents a behavioral characterization of the time course of Accelerated Long-Term Forgetting (ALF) in people with epilepsy (PWE). This chapter shows evidence of ALF on a shorter time scale than previous studies, with a differential impact on recall and recognition. Chapter 3 builds upon the work in Chapter 2 by extending ALF time points and investigating the …

Relationship Between Cognitive Performance, Physical Activity, And Socio-Demographic/ Individual Characteristics Among Aging Americans, Imtiaz Masfique Dowllah

Theses and Dissertations

Despite the attenuation of association following adjustments for covariates, participants who engaged in 3–6 hr/wk of vigorous- and > 1 hr/wk of moderate-intensity PA scored significantly higher in tests that assessed executive function and processing speed domains of cognition compared to inactive peers (η2 = 0.005 & 0.007 respectively, p < 0.05). Also, after adjustment, the effects of 1–3 hr/wk of vigorous-intensity PA became trivial for the delayed recall memory domain test scores (β = 0.33; 95% CI: –0.01, 0.67; η2 = 0.002; p = 0.56). There was no clear dose-response relationship between the cognitive test scores and weekly moderate-intensity PA. Interestingly, higher handgrip strength and higher late-life body-mass-index were associated with a higher performance across all cognitive domains. Observed associations provide evidence linking habitual PA with superior cognition health among older adults. Furthermore, increased muscle strength and higher late-life adiposity may …

Context Fear Memory Formation Is Regulated By Hippocampal Lncrna-Mediated Histone Methylation Changes, Anderson Alan Butler

All ETDs from UAB

The post-translational modification of histones regulates gene expression and is critical for the formation and maintenance of hippocampus-dependent long-term memories. Changes in gene-specific expression of various epigenetic marks during the aging pro-cess are sufficiently consistent as to be used as an aging landmark or epigenetic clock in both humans and other species; however, the molecular mechanisms which govern the application of these marks aging are poorly explored. Recently, long noncoding RNAs (lncRNAs) have been implicated as regulators of histone methyltransferases and other chromatin-modifying enzymes (CMEs). Despite the relevance of such mechanisms to both aging and memory formation, the behavioral relevance …

Defining The Radioresponse Of Mossy Cells, Devon Ivy

Electronic Theses, Projects, and Dissertations

Clinical radiotherapy is used to treat a variety of brain tumors within the central nervous system. While effective, it can result in progressive and debilitating cognitive impairment that can diminish quality of life. These impairments have been linked to hippocampal dysfunction and corresponding deficits in spatial learning and memory. Mossy cells are a major population of excitatory neurons located within the dentate hilus and highly involved in hippocampal circuitry. They play critical roles in spatial navigation, neurogenesis, memory, and are particularly vulnerable to a variety of neurotoxic insults. However, their sensitivity to ionizing radiation has yet to be investigated in …

Exercise, Learning And Emotional Health: Interdisciplinary Approaches To Translational Action, Tessa L. Koschel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Exercise positively effects physical, psychological and neurological wellbeing. Though the population at large is becoming increasingly aware of the multi-faceted benefits of exercise, the majority of people fail to meet daily exercise recommendations. Largely, demands of everyday life such as work, school and family take priority over fitness. The issue therefore becomes a matter of time. In a world of media multi-tasking and immediate gratification, the challenge to health professionals becomes incorporation and manipulation of these consistencies to improve exercise uptake and adherence. Focus must shift from the idea of making additional time for exercise, to adding exercise to time …

A Behavioral And Neuroimmune System Model Of The Effects Of Chronic Low-Level Lead Exposure In Young Male C57bl/6j Mice, Mayra Gisel Flores-Montoya

Open Access Theses & Dissertations

Chronic low-level lead exposure reduces memory in children however the brain mechanisms mediating these effects are not known. In previous studies we showed that early lead exposure reduced olfactory memory and exploratory behavior in young mice, and reduced microglia cell density in hippocampus/dentate gyrus. The present studies aimed to identify additional behavioral tests that were sensitive to early low-level lead exposure in young mice; and to examine whether microglia upregulated factors known to promote cell migration. Seventy-two C57BL/6J male mice were exposed to 0 ppm (controls), 30 ppm (low-dose), or 430 ppm (high-dose) of lead acetate via dams' milk from …

Neural Correlates Of Episodic Memory Formation In Children And Adults, Lingfei Tang

Wayne State University Theses

The medial temporal lobe (MTL) and prefrontal cortex (PFC) are two key brain regions that support episodic memory formation in both children and adults, but the functional developmental of these regions remains unclear. In this study, we investigated the development of neural correlates of episodic memory formation using functional MRI with a subsequent memory paradigm, administered to a cross-sectional sample of 83 children and adults. We found that MTL subregions showed an age-related increase in activation supporting memory formation of complex scenes. In addition, a functionally defined scene-sensitive region in the posterior MTL also showed similar increase and predicted better …

Age Related Decline In Memory: Examining The Mediation Effect Of Processing, Executive Functioning And Intelligence In Normal Adults, Jada J. Stewart

Theses and Dissertations

Multiple mediation analyses that collectively examine the prominent theories of cognitive aging (i.e., Common Cause, Processing, and Executive Decline Hypotheses) along with other cognitive domains that are sensitive to aging are rare. Moreover, having identified that cognition begins to decline as early as 30 years old, few studies have examined the mechanisms that underlie memory change among younger aging individuals. As a result, it is unclear whether relevant mediating variables have been excluded from early research on age-related memory decline, or to what extent rehabilitative strategies are applicable as early interventions for maintaining cognitive functioning into late life.

The present …

Obesity Weighs Down Memory: Emerging Insights Into The Epigentic Basis Of Obesity-Induced Memory Impairment In Adult Mice, Frankie Darryn Heyward

All ETDs from UAB

A preponderance of evidence has established that obesity contributes to memory impairments in mid-age adults. Empirical evidence has revealed that diet-induced obesity contributes to memory impairments in adult rodents. Precisely how obesity disrupts memory remains an open question. Bourgeoning data indicate that molecular epigenetic mechanisms mediate the changes in gene transcription that are necessary for hippocampus-dependent memory consolidation. Epigenetic mechanisms, such as DNA methylation, stably regulate gene expression without affecting the DNA sequence. Moreover, DNA methylation of memory-related genes with in the hippocampus is indispensible for memory formation. There is recent evidence of obesity-induced aberrantions in DNA methylation both peripherally …

Dna Methylation Regulates Neuronal Synaptic Scaling And Intrinsic Membrane Excitability, Jarrod P. Meadows

All ETDs from UAB

Learning and memory rely on long-lasting, experience-dependent adaptations in synaptic and non-synaptic forms of neuronal plasticity. Previous evidence implicates transcriptional and epigenetic mechanisms, including DNA cytosine methylation, as critical regulators of site-specific, Hebbian alterations in synaptic efficacy such as long-term potentiation (LTP) and long-term depression (LTD). However, whether DNA methylation modulates cell-wide, non-Hebbian homeostatic adaptations like synaptic scaling and intrinsic plasticity (IP) is unclear. Whereas synaptic scaling involves bidirectional changes in postsynaptic receptor density in response to chronic alterations in neuronal activity, IP involves the activity-dependent attunement of passive and/or active membrane properties that govern action potential (AP) firing. This …

Tethered Il-15 To Augment The Therapeutic Potential Of T Cells Expressing Chimeric Antigen Receptor: Maintaining Memory Potential, Persistence, And Antitumor Activity, Lenka Hurton

Dissertations & Theses (Open Access)

Tethered IL-15 to augment the therapeutic potential of T cells expressing chimeric antigen receptor: Maintaining memory potential, persistence, and antitumor activity

Adoptive immunotherapy can retarget T cells to CD19, a tumor-associated antigen (TAA) expressed on B-cell malignancies, by the expression of a chimeric antigen receptor (CAR). Infusion of CAR-modified T cells for the treatment B-cell malignancies has demonstrated promise in preclinical and clinical trials. These data highlight the ability of infused CD19-specific T cells to be synchronously activated by large burdens of CD19⁺ leukemia and lymphoma. This can lead to dramatic antitumor effects, but also exposes the recipient to …

Regulation Of Alpha Synuclein Following Chronic Methamphetamine Administration In Guinea Pigs: Correlation With Memory And Synaptic Plasticity, Adnouse Blanc

PCOM Biomedical Studies Student Scholarship

Methamphetamine (METH) is a highly addictive drug of abuse that has a severe impact on neuronal changes in the brain including modulations of plasticity, cognitive dysfunction, as well as memory impairment. These changes can be seen as modifications in the expression of biochemical markers associated with synaptic plasticity. One such marker associated with memory impairment is alpha synuclein (α-syn). Alteration of α-syn expression has been linked to memory impairment in patients with Alzheimer’s disease (AD) and Parkinson’s disease (PD). Here we assess the effect of chronic METH treatment in correlation to cognitive functions.

Twenty-nine guinea pigs (male, 150-250 g) were …

Molecular And Cellular Mechanisms Of Reelin Signaling In The Adult Hippocampus, Justin Howard Trotter

USF Tampa Graduate Theses and Dissertations

The Reelin signaling pathway is critical for neuronal migration during development and the function of excitatory synapses in the adult forebrain. Despite a growing body of evidence implicating impaired Reelin signaling in the pathogenesis of numerous neuropsychiatric and neurodegenerative disorders, including Schizophrenia and Alzheimer's disease, little is known still regarding the specific molecular and cellular mechanisms whereby Reelin signaling modulates the function of synapses to enable normal learning and memory. In this dissertation, we addressed these knowledge gaps by identifying mechanisms of Reelin proteolysis following synaptic potentiation (Chapter 2) and dissociated the synaptic function of Reelin signaling at excitatory (Chapter …

The Role Of Gadd45b In Hippocampus-Dependent Cognition, Synaptic Plasticity And Activity-Associated Transcriptional Dynamics, Faraz Sultan

All ETDs from UAB

An expanding body of literature argues for a pivotal role of molecular epigenetic mechanisms in memory. Defined as mechanisms that regulate gene expression in the absence of DNA sequence modifications, these regulate various stages of memory-associated transcription. These phenomena are present at diverse anatomical subregions of the central nervous system (CNS) and regulate corresponding behaviors. Epigenetic mechanisms comprise a unique category of behavioral and physiological modulators because of their potential to modify the cellular phenotype in a stable manner. Hence, epigenetics offers a novel potential solution to a central paradox in memory retention: the finding that most putative molecular substrates …

Intrinsic And Extrinsic Factors Required For Cd4 T Memory Cell Formation And Function, Sarah B. Mollo

All ETDs from UAB

CD4 T cells are central to the organization of the immune response through the secretion of cytokines that recruit and activate other immune cells. Following infection and pathogen control, the majority of the effector CD4 T cells undergo apoptosis, leaving a subset that persists and gives rise to the memory T cell pool. Upon encountering the same pathogen, memory CD4 T cells respond rapidly, providing enhanced protection from re-infection. What determines which effector CD4 T cells will survive is unclear; however, there are a number of factors both intrinsic to the cell as well as external signals from the environment …

Adhesion Molecule Interactions Influence The Implementation Of Immune Responses To Infection, Maureen Ann Cox

All ETDs from UAB

Interactions mediated by intercellular adhesion molecule-1 (ICAM-1) enhance both the antigenic and cytokine signals that CD8 T cells perceive, and these interactions have been suggested to be required for the formation of memory CD8 T cells. Following acute lymphocytic choriomeningitis virus (LCMV) infection of ICAM-1-/- mice, we observe elevated numbers of "effector-phenotype" (CD127lo KLRG-1hi IL-2-) virus-specific CD8 T cells well into the memory phase, while the development of memory-phenotype CD8 T cells (CD127hi KLRG-1lo IL-2 producing) is not impaired. The enhanced maintenance of effector-phenotype cells is due to ICAM-1 deficiency on non-T cell subsets, suggesting a role for ICAM-1 mediated …

Is Chronic Use Of Bacopa Monnieri An Effective Treatment To Improve Memory Performance In Healthy And Aging Adults?, Brian M. Kairalla

PCOM Physician Assistant Studies Student Scholarship

OBJECTIVE: The objective of the systematic review is to determine whether or not chronic use of Bacopa monnieri is an effective treatment to improve memory performance in healthy and aging adults.

Myosin Ii In Hippocampal Synapses: Regulation Of Synaptic Plasticity, Strength And Actin Dynamics By Two Distinct Isoforms, Maria Dolores Rubio

All ETDs from UAB

Cytoskeletal actin filaments underlie dendritic spine plasticity, critical for several forms of learning and memory. Therefore, understanding the mechanisms that regulate actin dynamics is essential to elucidate memory formation pathways. Myosins, a superfamily of actin binding proteins, have emerged as candidates for regulation of actin dynamics in the brain. Several myosin class II isoforms have been identified in brain, but their individual contribution to synaptic activity is still unknown. Based on the finding that myosin IIB regulates actin polymerization in the growth cone of developing neurons and that it is necessary for maintenance of dendritic spine structure, I hypothesized that …

The Development Of Humoral And Cellular Responses To Plasmodium Falciparum Malaria In The Hypoendemic Peruvian Amazon And Potential Clinical Protection, Eva Helen Clark

All ETDs from UAB

Each year 300-500 million cases of Plasmodium falciparum malaria occur, leading to more than 1 million deaths. In high malaria transmission regions, development of immunity from severe infection requires 2-10 years of persistent parasitemia. This delay has been attributed to difficulties in the development of protective humoral responses. Indeed, anti-malarial antibody responses tend to be short-lived, and immunologic memory seems to be dysfunctional in high-transmission regions. In contrast, in the low-transmission Peruvian Amazon >60% of infections are asymptomatic, suggesting that clinical immunity occurs despite low parasite exposure. To analyze more precisely the naturally-acquired humoral responses to malarial antigens and their …