Physiology Commons^™

Stress-Dependent Regulation Of A Major Node Of The Insulin-Like Peptide Network That Modulates Survival, Rashmi Chandra

Wayne State University Dissertations

Chronic stress disrupts insulin signaling, predisposing human populations to diabetes, cardiovascular disease, Alzheimer’s Disease, and other metabolic and neurological disorders, including post-traumatic disorders (PTSD). Thus, efficient recovery from stress optimizes survival. However, stress recovery in humans is difficult to study, but is much easier to dissect in model organisms. The worm genetic model Caenorhabditis elegans can switch between stressed and non-stressed states, and this switch is largely regulated by insulin signaling. Previously, the Alcedo lab proposed that insulin-like peptides (ILPs), which exist as multiple members of a protein family in both C. elegans and humans, implements a combinatorial coding strategy …

Synaptotagmin C2b Ca2+-Binding Loops Impose Distinct Exocytosis Phenotypes, Michael W. Schmidtke

Wayne State University Theses

Regulated exocytosis from chromaffin cells in the adrenal medulla plays a critical role in maintaining organismal homeostasis. In the absence of stress, these cells release physiologically relevant substances into the blood stream only in limited quantities, whereas stressful conditions result in a rapid deluge of signaling molecules used, for example, to increase heart rate and pain tolerance. Although the cellular mechanisms governing the switch from low-level to stress-induced secretion are not well understood, recent evidence has implicated the exocytotic Ca2+-sensing protein Synaptotagmin (Syt) in this role.

Two isoforms of Syt are expressed in chromaffin cells (Syt-1 and Syt-7), and each …

Estimating The Variables Of The Nonlinear Dynamical Theory Of Acute Cell Injury, Fika Tri Anggraini

Wayne State University Dissertations

This Dissertation is the first to estimate the variables D and S of the nonlinear theory of acute cell injury in hippocampal regions CA1 and CA3 using a rat model of global brain ischemia and reperfusion (I/R). D was estimated by quantifying protein aggregates using ubiquitin Western blotting. S was estimated by quantifying changes in polysomal mRNAs as measured by microarray chips. D and S time courses were sampled at 0.5, 8, 16, 24, 48, and 72 hrs of reperfusion after 10 min brain ischemia. CA1 dies and CA3 survives. The theory predicts D will be larger in CA1 and …

An Analysis Of Plasticity In The Rat Respiratory System Following Cervical Spinal Cord Injury And The Application Of Nanotechnology To Induce Or Enhance Recovery Of Diaphragm Function, Janelle Lorien Walker

Wayne State University Dissertations

Second cervical segment spinal cord hemisection (C2Hx) results in ipsilateral hemidiaphragm paralysis. However, the intact latent crossed phrenic pathway can restore function spontaneously over time or immediately following drug administration.

WGA bound fluorochromes were administered to identify nuclei associated with diaphragm function in both the acute and chronic C2Hx models. WGA is unique in that it undergoes receptor mediated endocytosis and is transsynaptically transported across select physiologically active synapses. Comparison of labeling in the acutely injured to the chronically injured rat provided an anatomical map of spinal and supraspinal injury induced synaptic plasticity. The plasticity occurs over time in the …

Role Of Secretory Granule Heterogeneity In Calcium-Triggered Exocytosis, Tejeshwar Rao

Wayne State University Dissertations

The sympathetic nervous system is activated by a variety of threats to organismal homeostasis. The adrenomedullary chromaffin cell is the core effector of sympathetic activity in the peripheral nervous system. By design, the chromaffin cell secretory response is mutable so that release can be rapidly tuned to drive context-dependent changes in physiological function. However, the mechanisms by which this tuning is achieved with such high temporal fidelity and context specificity remain unclear. This represents a major gap in our understanding of the sympatho-adrenal system since it is known to modify the function of nearly every organ system in the body. …

Unstable Ventilatory Control During Sleep After High Spinal Cord Injury: The Contribution Of Chemosensitivity And Hypoventilation, Amy Therese Bascom

Wayne State University Dissertations

ABSTRACT

UNSTABLE VENTILATORY CONTROL DURING SLEEP AFTER HIGH SPINAL CORD INJURY: THE CONTRIBUTION OF CHEMOSENSITIVITY AND HYPOVENTILATION

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Amy T. Bascom

May 2015

Advisor: Dr. Harry G. Goshgarian

Major: Anatomy and Cell Biology

Degree: Doctor of Philosophy

A high prevalence of sleep-disordered breathing (SDB) after spinal cord injury (SCI) has been reported in the literature; however, the underlying mechanisms are not well understood. My studies had 2 aims: 1) to determine the effect of the withdrawal of the wakefulness drive to breathe on the degree of hypoventilation in SCI patients and able-bodied controls and 2) to determine the response of …

Investigation Of Whether Sedentary And Physically Active Conditions Lead To Altered Gabaergic Signaling In The Rvlm, Maryetta Donna Dombrowski

Wayne State University Dissertations

Investigation of whether sedentary and physically active conditions lead to altered GABAergic signaling in the RVLM

MD Dombrowski, and PJ Mueller

Department of Physiology, Wayne State University, School of Medicine, Detroit, MI

A sedentary lifestyle is a major risk for cardiovascular disease. Cardiovascular disease has been associated with elevated basal sympathetic nerve activity. The rostral ventrolateral medulla is a bilateral brainstem region that is an important for the control of resting and reflex control of sympathetic nerve activity and blood pressure. The activity of these neurons in this region is tonically inhibited by the neurotransmitter γ-butyric amino acid (GABA). Interestingly, …

Blast-Induced Tinnitus: A Combined Behavioral, Memri, And Electrophysiology Study, Jessica Pengyun Ouyang

Wayne State University Dissertations

ABSTRACT

BLAST-INDUCED TINNITUS: A COMBINED BEHAVIORAL, MEMRE, AND ELECTROPHYSIOLOGY STUDY

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JESSICA OUYANG

May 2014 Advisor: Drs. Steve Cala & Jinsheng Zhang

Major: Physiology

Degree: Doctor of Philosophy

Tinnitus and hearing loss are the frequent auditory-related co-morbidities of blast trauma. The etiology of blast-induced tinnitus is also muddled by brain mechanisms associated with emotional and cognitive problems such as anxiety, memory loss, and depression. We set out to develop a realistic and ecologically valid model to address changes of cognitive status and psychological state that are associated with blast- induced tinnitus. In this study, 19 adult rats were randomly divided …

Mechanisms Of Persistent Translation Arrest Following Global Brain Ischemia And Reperfusion, Jill Theresa Jamison

Wayne State University Dissertations

ABSTRACT

MECHANISMS OF PERSISTENT TRANSLATION ARREST FOLLOWING GLOBAL BRAIN ISCHEMIA and REPERFUSION

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JILL T. JAMISON

December 2011

Advisor: Donald J. DeGracia, Ph.D.

Major: Physiology

Degree: Doctor of Philosophy

The information presented here studies the mechanisms that underlie persistent translation arrest (TA) following global brain ischemia and reperfusion (I/R). To summarize the main findings I have discovered a new mechanism for prolonged post-ischemic TA that correlated exactly with in vivo translation rates and correlated precisely with cell outcome. Through the extensive colocalization studies, my results indicate that the mRNA granules are ribonomic structures involved with mRNA regulation. This finding is …

Mechanisms Of Translation Arrest Following Focal Brain Ischemia, Monique K. Lewis

Wayne State University Dissertations

MECHANISMS OF TRANSLATION ARREST FOLLOWING FOCAL BRAIN

ISCHEMIA

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MONIQUE K. LEWIS

August 2011

Advisor: Dr. Donald DeGracia

Major: Physiology

Degree: Doctor of Philosophy

The loss of blood flow to the brain is termed ischemia and the subsequent resumption of blood flow is termed reperfusion. Brain ischemia and reperfusion (I/R) occurs primarily following resuscitation from cardiac arrest and stroke and presents one of the most significant clinical challenges. At present, there are no clinically effective pharmacologic interventions to halt brain damage following I/R. The major Aim of this dissertation will be to investigate possible mechanisms involved in neuron death following …