Files in this item



application/pdf3153401.pdf (11MB)Restricted to U of Illinois
(no description provided)PDF


Title:The Pedunculopontine Nucleus: A Potential Site of Respiratory Modulation During Muscle Contraction and Hypoxia
Author(s):Plowey, Edward Douglas
Doctoral Committee Chair(s):Waldrop, Tony G.
Department / Program:Molecular and Integrative Physiology
Discipline:Molecular and Integrative Physiology
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Biology, Neuroscience
Abstract:The studies contained in this dissertation begin to examine a potential role for the pedunculopontine nucleus (PPN) in the regulation of respiratory adjustments that accompany motor activity and hypoxia. The PPN, located in the dorsal mesencephalic tegmentum at the lateral extent of the brachium conjunctivum, has previously been implicated in regulation of cardiorespiratory adjustments that accompany physical activity through a feed-forward mechanism termed "central command". The primary goal of this dissertation was to address the hypothesis that the PPN mediates influences on reflex respiratory adjustments that accompany skeletal muscle contraction in anesthetized rats. Extracellular single-unit electrophysiologic recordings were employed in the first group of studies to demonstrate that individual PPN neurons exhibited increases in firing rate during activation of muscle reflex pathways during static muscle contraction. Activation of PPN neurons was shown to have functional significance in that microinjections of bicuculline, a GABAA receptor antagonist, into the PPN resulted in significant increases in respiratory activity. The second set of studies demonstrated importance of the integrity of pathways that synapse in the PPN to the respiratory responses observed during muscle contraction in that injections of CoCl2 into the PPN resulted in significant attenuation of the reflex diaphragmatic responses to muscle contraction. Finally, responses of PPN neurons were also examined during hypoxia-related stimuli. PPN neurons were found to exhibit increases in firing rate during systemic hypoxia in anesthetized adult rats. However, inhibitory responses during chemical hypoxia were documented amongst most PPN neurons recorded in brain slice preparations from neonatal rats. The results of the studies that comprise this dissertation suggest that the PPN may mediate influences on the respiratory system during physical activity and hypoxia and that the PPN warrants future attention to elucidate its role in the regulation of respiratory adjustments in these and other physiologic and pathophysiologic contexts.
Issue Date:2004
Description:139 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2004.
Other Identifier(s):(MiAaPQ)AAI3153401
Date Available in IDEALS:2015-09-28
Date Deposited:2004

This item appears in the following Collection(s)

Item Statistics