Publication Date
2013
Document Type
Thesis
Committee Members
David Goldstein (Committee Member), Lynn Hartzler (Advisor), Robert Putnam (Committee Member)
Degree Name
Master of Science (MS)
Abstract
The locus coeruleus (LC) in the brainstem senses alterations in CO2/pH and influences ventilatory adjustments that restore blood gas values to starting levels in bullfrogs (Lithobates catesbeianus). We hypothesized that neurons of the bullfrog LC are sensitive to changes in CO2/pH and that chemosensitive responses are intrinsic to individual neurons. In addition, we hypothesized putative respiratory control neurons of the bullfrog LC would be stimulated by hypercapnic acidosis within physiological ranges of PCO2/pH. 84% of LC neurons depolarized and increased firing rates during exposure to hypercapnic acidosis (HA). A pH dose response curve shows LC neurons from bullfrogs increase firing rates during physiologically relevant CO2/pH changes. With chemical synapses blocked, half of chemosensitive neurons lost sensitivity to HA; however, gap junction blockade did not alter chemosensitive responses. Intrinsically chemosensitive neurons increased input resistance during HA. These data demonstrate that the majority of neurons within the bullfrog LC elicit robust firing responses during physiological CO2/pH, likely enabling adjustment of acid-base balance through breathing.
Page Count
77
Department or Program
Department of Biological Sciences
Year Degree Awarded
2013
Copyright
Copyright 2013, some rights reserved. My ETD may be copied and distributed only for non-commercial purposes and may not be modified. All use must give me credit as the original author.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
