The Pedunculopontine Nucleus: A Potential Site of Respiratory Modulation During Muscle Contraction and Hypoxia
Plowey, Edward Douglas
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/87231
Description
Title
The Pedunculopontine Nucleus: A Potential Site of Respiratory Modulation During Muscle Contraction and Hypoxia
Author(s)
Plowey, Edward Douglas
Issue Date
2004
Doctoral Committee Chair(s)
Waldrop, Tony G.
Department of Study
Molecular and Integrative Physiology
Discipline
Molecular and Integrative Physiology
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Biology, Neuroscience
Language
eng
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."
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
