Temperature and pH/CO(2) modulate respiratory activity in the isolated brainstem of the bullfrog (Rana catesbeiana)

The effects of temperature and pH/CO(2) were examined in isolated brainstem preparations from adult North American bullfrogs (Rana catesbeiana). These experiments were undertaken to determine the effects of temperature on fictive breathing, central pH/CO(2) chemoreception, and to examine potential a...

Full description

Saved in:
Bibliographic Details
Published in:Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Molecular & integrative physiology, 2002-06, Vol.132 (2), p.477
Main Authors: Morales, Rey D, Hedrick, Michael S
Format: Article
Language:English
Subjects:
Animals
Brain Stem - drug effects
Brain Stem - physiology
Carbon Dioxide - pharmacology
Electrophysiology
Environmental Exposure
Hydrogen-Ion Concentration
In Vitro Techniques
Rana catesbeiana - physiology
Respiration - drug effects
Temperature
Tidal Volume
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The effects of temperature and pH/CO(2) were examined in isolated brainstem preparations from adult North American bullfrogs (Rana catesbeiana). These experiments were undertaken to determine the effects of temperature on fictive breathing, central pH/CO(2) chemoreception, and to examine potential alphastat regulation of respiration in vitro. Adult bullfrog brainstem preparations were isolated, superfused with an artificial cerebrospinal fluid (aCSF) and respiratory-related neural activity was recorded from cranial nerves V, X and XII. In Series I experiments (N=8), brainstem preparations were superfused with aCSF equilibrated with 2% CO(2) at temperatures ranging from 10 to 30 degrees C. Neural activity was present in all preparations in the temperature range of 15-25 degrees C, but was absent in most preparations when aCSF was at 10 or 30 degrees C. The absence of fictive breathing at high (30 degrees C) temperatures was transient since fictive breathing could be restored upon returning the preparation to 20 degrees C. In Series II experiments (N=10), preparations were superfused with aCSF equilibrated with 0%, 2% and 5% CO(2) at temperatures of 15, 20 and 25 degrees C. Fictive breathing frequency (f(R)) was significantly dependent upon aCSF pH at all three temperatures, with slopes ranging from -0.82 min(-1) pH unit(-1) (15 degrees C) to -3.3 min(-1) pH unit(-1) (20 degrees C). There was a significant difference in these slopes (P
ISSN:1095-6433