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Title: Investigation of the efficacy of various neuroprotection agents for their potential use in the treatment of Parkinson's disease
Creator: Janis, Kelly Lynn
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Role of NADPH oxidase in peripheral sympathetic and sensory neurons in hypertension
Creator: Cao, Xian
Date: 2008
Collection: Electronic Theses & Dissertations

Title: The effect of sad mood on pain perception : imaging functional brain networks
Creator: Yang, Lan
Date: 2012
Collection: Electronic Theses & Dissertations
Description: People with chronic pain are often afflicted with psychiatric depressive disorders. Even the commonplace, everday experience of pain can be modified by ordinary emotion. However, the neural mechanisms underlying these phenomena are still unclear. Investigating the effects of sad mood on pain perception at the behavioral and the neural levels helps to understand the co-morbidity of depression and pain problems. This dissertation focuses on: (1) examining the effects of sad mood on perception...
Show morePeople with chronic pain are often afflicted with psychiatric depressive disorders. Even the commonplace, everday experience of pain can be modified by ordinary emotion. However, the neural mechanisms underlying these phenomena are still unclear. Investigating the effects of sad mood on pain perception at the behavioral and the neural levels helps to understand the co-morbidity of depression and pain problems. This dissertation focuses on: (1) examining the effects of sad mood on perception of painful stimuli, and (2) identifying the functional brain networks that could provide the neural substrate for pain perception altered by sadness.In Chapter 2, a task-evoked functional magnetic resonance imaging (fMRI) method has been used to investigate which brain areas are activated by painful and emotional stimuli. The hypotheses are that the subjective perception of pain intensity would be greater during sadness compared to neutral mood, and significantly increased neural activation would be observed in the primary cortical areas for pain perception. To test these hypotheses, the fMRI study has recruited sixteen healthy female subjects. The experimental trials include the delivery of painful electrical shocks concurrent with or without sad mood induced by the presentation of pictures from the International Affective Picture System (IAPS). The study identifies widely-distributed cortical and subcortical areas involved in the processing of pain and the altered pain perception by sadness. The cortical areas for pain processing are mainly located in the primary/secondary somatosensory, insular and cingulate cortices. Specifically, the posterior insular and the adjacent secondary somatosensory cortices (pIn/SII) have significantly increased neural activation, when sadness intensifies subjective perception of pain.In Chapter 3, using the resting-state fMRI and path analysis, it further examines the functional networks of pain processing and altered pain perception by sadness. The pain-relevant brain areas, such as primary somatosensory cortex, anterior cingulate cortex and thalamus, are intrinsically correlated with pIn/SII during rest. The path coefficients in the pain processing functional brain network increase during painful stimuli. The path analysis has also revealed a functional network in which the pIn/SII connects with emotion-relevant areas, such as the subgenual cingulate cortex, anterior insula and amygdala. These findings provided evidence of specific neural pathways that may be relevant to understanding the comorbidity of depression and pain problems.
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Title: Sexual dimorphisms and androgen influence in medial posterodorsal amygdala astrocytes
Creator: Johnson, Ryan T.
Date: 2011
Collection: Electronic Theses & Dissertations
Description: The amygdala is a highly interconnected brain region involved in fear, anxiety, social and reproductive behaviors. In humans and laboratory species the amygdala exhibits sexual dimorphisms in neuroanatomy and function both in juveniles and adults. In rodents, the medial posterodorsal amygdala (MePD) is particularly sexually dimorphic and gonadal hormone sensitive, and while neurons have been examined in this region, few reports have examined the potential influence of gonadal hormones on...
Show moreThe amygdala is a highly interconnected brain region involved in fear, anxiety, social and reproductive behaviors. In humans and laboratory species the amygdala exhibits sexual dimorphisms in neuroanatomy and function both in juveniles and adults. In rodents, the medial posterodorsal amygdala (MePD) is particularly sexually dimorphic and gonadal hormone sensitive, and while neurons have been examined in this region, few reports have examined the potential influence of gonadal hormones on other cellular components of the MePD. Astrocytes are a subtype of glia involved in synapse formation and known to be plastic and dynamic cells sensitive to gonadal hormone influence in several brain regions. My dissertation reveals sexual dimorphisms in the number of astrocytes in the juvenile rat MePD and that this sexual dimorphism remains present in adult animals. I also found sex differences in the arbor complexity of astrocytes in adults that are not present prior to puberty. Astrocytes also respond to changes in circulating hormone levels in adulthood. Furthermore, while the sex difference in astrocyte numbers in juvenile animals is androgen receptor-independent, the sex differences found in adult astrocyte numbers and arbor complexity are both androgen receptor-dependent. Finally, I provide evidence that astrocytes in the MePD contain androgen receptors, suggesting that androgens may act directly on these cells. The influence of gonadal hormones on astrocytes in the MePD is likely an important part of pubertal development and has implications for our understanding of the cellular organization of the amygdala and its function.
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Title: Mechanisms of R-type calcium channel regulation in the enteric nervous system
Creator: Naidoo, Vinogran
Date: 2009
Collection: Electronic Theses & Dissertations

Title: Neurodynamics of episodic memory consolidation
Creator: Smith, Jeremy Lee
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Unveiling diet-induced obesity : leptin insensitivity and dysregulation of the HPA axis
Creator: Shin, Andrew Changhun
Date: 2008
Collection: Electronic Theses & Dissertations

Title: The neurodevelopmental effects of chronic moderate prenatal caffeine exposure in rats
Creator: Soellner, Deborah Elizabeth
Date: 2009
Collection: Electronic Theses & Dissertations

Title: Characterization of novel groups of catecholaminergic cells in the male prairie vole extended amygdala
Creator: Northcutt, Katharine Virginia
Date: 2010
Collection: Electronic Theses & Dissertations

Title: When androgen receptors go awry : muscle specific expression triggers Spinal Bulbar Muscular Atrophy (SBMA)
Creator: Johansen, Jamie Ann
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Characterization of the differential susceptibility of dopamine neuronal populations in a mouse model of Parkinson's disease
Creator: Behrouz, Bahareh
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Adolescent anabolic steroid exposure : effects on social behaviors and neural plasticity
Creator: Salas-Ramirez, Kaliris Y.
Date: 2007
Collection: Electronic Theses & Dissertations

Title: Impaired purinergic neurotransmission to mesenteric arteries in salt-sensitive hypertension
Creator: Demel, Stacie Leigh
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Neural and endocrine mechanisms underlying adolescent maturation of social reward
Creator: Bell, Margaret R.
Date: 2012
Collection: Electronic Theses & Dissertations
Description: The adolescent transition from childhood to adulthood requires a qualitative shift in the focus on social interactions and reward. The male Syrian hamster provides a unique model for understanding how social information processing matures throughout adolescence, as juvenile males are not attracted to female vaginal secretions (VS) that are essential for sexual behavior in adulthood. I have shown that VS are rewarding in gonad-intact adult but not juvenile hamsters using conditioned place...
Show moreThe adolescent transition from childhood to adulthood requires a qualitative shift in the focus on social interactions and reward. The male Syrian hamster provides a unique model for understanding how social information processing matures throughout adolescence, as juvenile males are not attracted to female vaginal secretions (VS) that are essential for sexual behavior in adulthood. I have shown that VS are rewarding in gonad-intact adult but not juvenile hamsters using conditioned place preference (CPP), and that testosterone treatment facilitates a VS-induced CPP in juveniles that is dopamine dependent. Moreover, VS induces Fos expression throughout the mesocorticolimbic system in adult but not juvenile hamsters. This body of work demonstrates that 1) the pubertal rise in testosterone changes the perception of a social stimulus, allowing it to serve as an unconditioned reward; 2) adolescent maturation of social reward is mediated by dopaminergic mechanisms and involves engagement of the mesocorticolimbic reward system.
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Title: Plasma aldosterone levels increase after cerebral ischemia, and mineralocorticoid receptor antagonism at the time of reperfusion reduces infarct size; the role of mineralocorticoid receptor antagonism on the inflammatory response post-stroke
Creator: Dams Ramos, Carla Maria
Date: 2012
Collection: Electronic Theses & Dissertations
Description: Stroke is a leading cause of death and disability, and the available therapies are limited. Stroke stimulates inflammatory mechanisms that exacerbate the damage caused by cerebral ischemia. Interestingly, inflammation is linked to the effects of aldosterone and mineralocorticoid receptor (MR) activation in different organ systems. Previous studies show that chronic MR antagonism before cerebral ischemia improves the outcome of stroke, and MR activation worsens it. The aim of this study was...
Show moreStroke is a leading cause of death and disability, and the available therapies are limited. Stroke stimulates inflammatory mechanisms that exacerbate the damage caused by cerebral ischemia. Interestingly, inflammation is linked to the effects of aldosterone and mineralocorticoid receptor (MR) activation in different organ systems. Previous studies show that chronic MR antagonism before cerebral ischemia improves the outcome of stroke, and MR activation worsens it. The aim of this study was investigate the hypothesis that plasma aldosterone levels increase after cerebral ischemia, and MR antagonists administered post-stroke, will reduce the infarct size by mediating a shift in the phenotype of the immune cells in the brain from pro- to anti-inflammatory. I induced transient focal cerebral ischemia using the middle cerebral artery occlusion technique, and the MR antagonist spironolactone was administered at the time of reperfusion. Plasma aldosterone levels were measured by ELISA, and inflammatory marker expression was analyzed by qRT-PCR. My results indicate that plasma aldosterone levels increase rapidly after the induction of cerebral ischemia in Wistar Kyoto (WKY) rats but not in stroke-prone spontaneously hypertensive rats (SHRSP). MR antagonism post-stroke reduced infarct size in both strains. In SHRSP, but not in WKY rats, MR antagonism increased the expression of anti-inflammatory microglia/macrophages and cytokines, which may be positive for stroke outcome. These results suggest that aldosterone post-stroke exacerbates the injury caused by cerebral ischemia and that MR antagonists are a potential drug for the treatment of stroke.
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Title: Investigating the role of mitochondria in disease and aging
Creator: Baqri, Rehan Murtaza
Date: 2011
Collection: Electronic Theses & Dissertations
Description: Mitochondria are central regulators of multiple critical cellular processes. Mitochondrial dysfunction, therefore, severely compromises cellular integrity. Mutations in mitochondrial DNA (mtDNA), dysfunction of the electron transport chain, excessive oxidative stress, imbalance in mitochondrial turnover, disruption of the fusion/ fission machinery, impaired trafficking, and defective mitochondrial proteostasis are widely implicated in disease pathology and organismal aging. However, less is...
Show moreMitochondria are central regulators of multiple critical cellular processes. Mitochondrial dysfunction, therefore, severely compromises cellular integrity. Mutations in mitochondrial DNA (mtDNA), dysfunction of the electron transport chain, excessive oxidative stress, imbalance in mitochondrial turnover, disruption of the fusion/ fission machinery, impaired trafficking, and defective mitochondrial proteostasis are widely implicated in disease pathology and organismal aging. However, less is understood about the interdependence of these different aspects of mitochondrial biology. For example, it is unclear how mtDNA depletion impacts mitochondrial trafficking. Similarly, the effect of increased oxidative stress on mitochondrial proteostasis is unknown. In this dissertation, I have investigated the regulation of mitochondrial dynamics in the context of mtDNA disorders, and the regulation of the mitochondrial proteostasis machinery in the context of aging and healthy lifespan.In Chapter 2, I will discuss the implications of blocking mtDNA replication on mitochondrial biogenesis, distribution and trafficking. We demonstrate that mtDNA depletion results in an upregulation of mitochondrial biogenesis and increased bidirectional axonal transport in Drosophila. Transport of other axonal cargoes is largely unaffected, indicating a specific regulation of mitochondrial axonal transport. We interpret these results in the context of an SOS response that is activated to replenish the presynaptic terminal with functional mitochondria. These data uncover a novel contributory mechanism in distal neuropathy, often associated with mtDNA disorders. In Chapter 3, I will present evidence that a mitochondrial chaperone TRAP1 is involved in regulating resistance to oxidative stress in Drosophila. Interestingly, there is only a marginal influence on lifespan, challenging the conventional belief that oxidative stress resistance is causally associated with longevity. Remarkably, dosage modulation of this mitochondrial chaperone has dramatic effects on the fitness and health of aging flies. This role of TRAP1 is mediated at least partially through the activation of the mitochondrial unfolded protein response. We discuss these results in the context of organismal aging and healthspan.Taken together, this dissertation has uncovered novel mechanisms by which mitochondria deal with at least two different stressors, mtDNA depletion and oxidative stress. In Chapter 4, I will discuss my findings in the perspective of mitochondrial quality control and its larger implications in human diseases and health. I will also briefly explore unanswered questions that arise from my work and the directions of future research and avenues open.
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Title: Neural mechanisms of female zebra finch mate choice : the role of the auditory perception sites, the social behavior network, and the reward system
Creator: Svec, Lace Ann
Date: 2009
Collection: Electronic Theses & Dissertations

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