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Sustained Stimulus Paradigms and Sexual Dimorphism of the Aortic Baroreflex in Rat

Indiana University-Purdue University Indianapolis (IUPUI) / The neurophysiological pathways associated with beat-to-beat regulation of mean
arterial pressure are well known. Less known are the control dynamics associated
with short term maintained of arterial blood pressure about a homeostatic set point.
The barorefex (BRx), the most rapid and robust of neural refexes within the autonomic
nervous system, is a negative feedback controller that monitors and regulates
heart rate and blood pressure. By leveraging the parasympathetic and sympathetic
divisions of the autonomic nervous system, the BRx can change blood pressure within
a single heart beat. To better understand these controller dynamics, a classic BRx
refexogenic experimental preparation was carried out. This thesis recon rmed previous
observations of an electrically-evoked sexually-dimorphic peak depressor response
in the BRx of Sprague-Dawley rats and veri ed that these functional refexogenic
differences carry over to sustained electrical paradigms. Further, it uncovered interesting
recovery dynamics in both blood pressure and heart rate. The rat aortic
depressor nerve was used as an experimental target for electrical activation of the
parasympathetic-mediated reduction in mean arterial pressure. The duration, frequency,
and patterning of stimulation were explored, with emphasis on differences
between sexes. By measuring the normalized percent decrease in mean arterial pressure
as well as the differences in beats per minute during rest and during stimulation,
the null hypothesis was rejected.

Identiferoai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/19010
Date05 1900
CreatorsMintch, Landan M.
ContributorsSchild, John, Yoshida, Ken, Mirro, Michael
Source SetsIndiana University-Purdue University Indianapolis
Languageen_US
Detected LanguageEnglish
TypeThesis
RightsAttribution 3.0 United States, http://creativecommons.org/licenses/by/3.0/us/

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