Physiology Commons^™

Action Potential Subpopulations In Human Muscle Sympathetic Nerve Activity: Discharge Properties And Governing Mechanisms, Stephen A. Klassen

Electronic Thesis and Dissertation Repository

What discharge properties are expressed by varying-sized sympathetic action potential (AP) subpopulations active under baseline conditions in humans and what are the governing mechanisms? To address this overall question the microneurographic approach was employed to record multi-unit muscle sympathetic nerve activity (MSNA), after which a continuous wavelet transform exposed APs in the recorded neurogram. Study One examined the role of the paravertebral ganglia on sympathetic neural discharge patterns. Through trimethaphan infusion under baseline conditions, this study revealed ordered de-recruitment of larger to smaller AP clusters, suggesting that the paravertebral ganglia contribute to the distribution of firing probabilities expressed by differently-sized …

A Comparison Of Lung Function Values Among A Scuba Diver Population And In Comparison To A Non-Diver Population, Gabriel C. Hutson, Jeremy D. Rentsch, Erin M. Eaton

Journal of the South Carolina Academy of Science

The purpose of this study was to investigate possible correlations between lung function values (PEF, IRV, ERV, and FVC) among a diver population, as well as in comparison to a non-diver population. Independent variables for both populations were biological sex, age, and weekly physical activity. Independent variables for the diver population were dive tenure, number of logged dives, certification level, and gas mixture used. A spirometry test was conducted to collect lung function values of both populations. Data from this study suggest a statistically significant relationship between diver and non-diver sex and FVC, diver age and ERV, diver sex and …

Is Professional Breath-Hold Diving Associated With Endothelial Dysfunction?, Emilie Woehrle

Electronic Thesis and Dissertation Repository

Professional breath-hold diving has been linked to acute dangers; however, the long-term impacts on vascular health are unknown. The endothelium releases vasodilator substances and its functionality is an indicator of vascular health. We are testing the hypothesis that chronic exposure to severe hypoxia may alter endothelial function in breath hold divers. Divers and controls completed a flow-mediated dilation (FMD) protocol, where brachial blood flow velocity was measured following blood flow occlusion. Percent FMD was calculated as the primary measure of endothelial function. T-tests assessed the statistical significance of between-group differences. The %FMD were similar between groups (p >0.05); however, divers …

Critical Embodied Praxis For Social Justice And Peace Educators: A Story Of Personal Transformation Through Analysis Of My Jewish And Settler Identities, Cara Michelle Silverberg

Capstone Collection

In this paper, I examine definitions of and relationships between violence, oppression, peace, liberation, and embodiment in the context of critical pedagogy in order to construct a theory of critical embodied praxis for social justice and peace educators. Considering the body to be a tangible vessel through which narratives and mechanisms of violence are expressed and maintained, I explore the potential of the body to be a vessel through which liberatory narratives may be generated and shared. After constructing a theory of critical embodied praxis, I illustrate this framework in action through a personal narrative that explores the intersections …

The Role Of Inflammatory Pathways In Development, Growth, And Metabolism Of Skeletal Muscle In Iugr Offspring; Blood Gene Expression Of Inflammatory Factors As Novel Biomarkers For Assessing Stress And Wellbeing In Exotic Species., Robert J. Posont

Department of Animal Science: Dissertations, Theses, and Student Research

Our first study identified the effects of maternal inflammation-induced intrauterine growth restriction (MI-IUGR) on growth and muscle glucose metabolism in offspring supplemented with curcumin. MI-IUGR lambs exhibited asymmetric growth restriction at birth and 30d of age, but normal glucose-stimulated insulin secretion. Hindlimb glucose oxidation was reduced by MI-IUGR and not improved by curcumin supplementation. Ex vivo muscle glucose oxidation was reduced by MI-IUGR but improved somewhat by curcumin. These finding indicate that fetal programming responses to MI contribute to neonatal growth and metabolic deficits. Neonatal curcumin supplementation had minimal effect on growth deficits but may improve glucose metabolism. …

The Orexin System In Doca-Salt Hypertension: Regulation Of Vasopressin, Jeremy Bigalke

Dissertations, Master's Theses and Master's Reports

Orexin is a neuropeptide with a large range of functions, with a recently discovered role in blood pressure (BP) regulation. Although the role of brain orexin system in hypertension has been investigated in several hypertensive animals, it remains unclear whether activation of the orexin system contributes to the development of Deoxycorticosterone-acetate (DOCA) hypertension, an animal model of human salt sensitive hypertension. In this study, we investigated the hypothesis that Orexin-1 receptor (OX1R) expression is increased in the paraventricular nucleus (PVN), a critical brain area controlling cardiovascular function, which subsequently increases vasopressin (AVP) expression and peripheral secretion, resulting in hypertension development …

Autonomic And Redox Imbalance Correlates With T-Lymphocyte Inflammation In A Model Of Chronic Social Defeat Stress, Cassandra M. Moshfegh, Safwan K. Elkhatib, Christopher W. Collins, Allison J. Kohl, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Patients diagnosed with post-traumatic stress disorder (PTSD) are at a significantly elevated risk of developing comorbid inflammatory conditions, but the mechanisms underlying this predilection remain unclear. Our previous work has shown that T-lymphocytes exposed to elevated levels of norepinephrine (NE) displayed a pro-inflammatory signature reminiscent of an autoreactive phenotype. With this, we hypothesized that the increased sympathetic tone observed during psychological trauma may be promoting pro-inflammatory T-lymphocytes, which causes a predisposition to comorbid inflammatory conditions. Here, we examined the consequences of psychological trauma on splenic T-lymphocytes using a mouse model of repeated social defeat stress. Social defeat led to anxiety-like …

Redox Biology In Physiology And Disease, Matthew C. Zimmerman, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

No abstract provided.

Central Glucagon-Like Peptide-1 Receptor Signaling Via Brainstem Catecholamine Neurons Counteracts Hypertension In Spontaneously Hypertensive Rats, Kenichi Katsurada, Masanori Nakata, Toshinobu Saito, Boyang Zhang, Yuko Maejima, Shyam Sundar Nandi, Neeru M. Sharma, Kaushik K. Patel, Kazuomi Kario, Toshihiko Yada

Journal Articles: Cellular & Integrative Physiology

Glucagon-like peptide-1 receptor (GLP-1R) agonists, widely used to treat type 2 diabetes, reduce blood pressure (BP) in hypertensive patients. Whether this action involves central mechanisms is unknown. We here report that repeated lateral ventricular (LV) injection of GLP-1R agonist, liraglutide, once daily for 15 days counteracted the development of hypertension in spontaneously hypertensive rats (SHR). In parallel, it suppressed urinary norepinephrine excretion, and induced c-Fos expressions in the area postrema (AP) and nucleus tractus solitarius (NTS) of brainstem including the NTS neurons immunoreactive to dopamine beta-hydroxylase (DBH). Acute administration of liraglutide into fourth ventricle, the area with easy access to …

Redox-Sensitive Calcium/Calmodulin-Dependent Protein Kinase Iiα In Angiotensin Ii Intra-Neuronal Signaling And Hypertension, Urmi Basu, Adam J. Case, Jinxu Liu, Jun Tian, Yulong Li, Matthew C. Zimmerman

Journal Articles: Cellular & Integrative Physiology

Dysregulation of brain angiotensin II (AngII) signaling results in modulation of neuronal ion channel activity, an increase in neuronal firing, enhanced sympathoexcitation, and subsequently elevated blood pressure. Studies over the past two decades have shown that these AngII responses are mediated, in part, by reactive oxygen species (ROS). However, the redox-sensitive target(s) that are directly acted upon by these ROS to execute the AngII pathophysiological responses in neurons remain unclear. Calcium/calmodulin-dependent protein kinase II (CaMKII) is an AngII-activated intra-neuronal signaling protein, which has been suggested to be redox sensitive as overexpressing the antioxidant enzyme superoxide dismutase attenuates AngII-induced activation of …

Total Energy Intake And Self-Selected Macronutrient Distribution During Wildland Fire Suppression, Alexander N. Marks, Joseph A. Sol, Joseph W. Domitrovich, Molly R. West, Brent C. Ruby

Graduate Student Theses, Dissertations, & Professional Papers

Introduction: Wildland firefighters (WLFF) work long hours in extreme environments resulting in high daily total energy expenditure (TEE). Increasing work shift eating episodes and/or providing rations that promote convenient feeding has shown augmented self-selected work output, as has regular carbohydrate (CHO) consumption. It remains unclear how current WLFF feeding strategies compare to more frequent nutrient delivery. Our study’s aim was to determine WLFFs’ self-selected field total energy intake (TEI), composition, and patterns feeding during wildland fire suppression shifts.

Methods: 86 WLFF (16 female, 70 male; 27.5 ± 6.4 yr) deployed to fire incidents across the United States throughout the 2018 …

Cold Tolerance, Temperature Mediated Discontinuous Gas Exchange, And Emergence Of The Blue Orchard Mason Bee (Osmia Lignaria), Logan Kral

All Master's Theses

The relationship between low temperatures, emergence and supercooling point of Osmia lignaria were the subject of this study. One hundred sixty-eight bees were subjected to 5 pre-wintering temperature treatments (two constant temperature controls - 22^oC, 14^oC, one of which with and one without a 12h photoperiod, and three 12h:12h thermoperiod treatments – 14:10^oC, 14:5^oC, and 14:0^oC) and were then evaluated in terms of emergence time and post-emergence vigor. An additional 70 bees were tested for metabolic rate and discontinuous gas exchange in response to test temperature conditions. An additional sample …

A Hybrid Cognitive Architecture With Primal Affect And Physiology, Christopher L. Dancy

Faculty Journal Articles

Though computational cognitive architectures have been used to study several processes associated with human behavior, the study of integration of affect and emotion in these processes has been relatively sparse. Theory from affective science and affective neuroscience can be used to systematically integrate affect into cognitive architectures, particularly in areas where cognitive system behavior is known to be associated with physiological structure and behavior. I introduce a unified theory and model of human behavior that integrates physiology and primal affect with cognitive processes in a cognitive architecture. This new architecture gives a more tractable, mechanistic way to simulate affect-cognition interactions …

Effects Of Acute Hypoxia On Danio Rerio, Karly Crail

Williams Honors College, Honors Research Projects

The purpose of this research experiment was to determine the effects of acute hypoxia on the embryonic zebrafish (Danio rerio) cardiovascular system and assess the critical oxygen level at which embryonic function is compromised. This goal was achieved by exposing embryos to decreasing oxygen concentrations, (6.0 mg/L-0 mg/L) and observing the heart under an inverted microscope. Data analysis was conducted to determine end systolic volume, end diastolic volume, stroke volume, heart rate, and cardiac output. It was hypothesized that hypoxia would stimulate cardiac activity, because in early developmental stages, tissues are supplied with oxygen through bulk diffusion, and …