TY - JOUR
T1 - Time-dependent changes in spontaneous respiratory activity in turtle brainstems in vitro
AU - Wilkerson, J. E R
AU - Wenninger, M. R.
AU - Mitchell, G. S.
AU - Johnson, S. M.
N1 - Funding Information:
This work was supported by Grants 60028 and 53319 from the Heart, Lung, and Blood Institute, National Institutes of Health (USA). J.E.R.W. was supported by a National Science Foundation Postdoctoral Fellowship.
PY - 2003/11/14
Y1 - 2003/11/14
N2 - Our goal was to determine whether time-dependent changes in respiratory motor output in vitro could be minimized by altering bath solution composition. Adult turtle brainstems were bathed in standard solution, nutrient-rich Dulbecco's Eagle media (100 or 25% concentration), or standard solution with phenylbiguanide (PBG, 5-HT3 agonist which increases respiratory drive). Except for a 63% frequency increase in PBG solution, hypoglossal bursts were unaltered within 100 min of observation. Respiratory activity was abolished within 7 h in 100% Dulbecco's compared with a mean of 24-31 h in other test solutions. At 12 h, burst frequency decreased faster in standard solution and 25% Dulbecco's (-0.28±0.07 and -0.13±0.05 bursts/h, respectively) compared with PBG solution (-0.09±0.04 bursts/h); amplitude declined at ∼2%/h in all solutions. The tendency for episodic discharge decreased gradually in standard solution, but was eliminated in 25% Dulbecco's and PBG solution. Certain bath solutions may minimize time-dependent frequency reductions but may also cause breathing pattern changes.
AB - Our goal was to determine whether time-dependent changes in respiratory motor output in vitro could be minimized by altering bath solution composition. Adult turtle brainstems were bathed in standard solution, nutrient-rich Dulbecco's Eagle media (100 or 25% concentration), or standard solution with phenylbiguanide (PBG, 5-HT3 agonist which increases respiratory drive). Except for a 63% frequency increase in PBG solution, hypoglossal bursts were unaltered within 100 min of observation. Respiratory activity was abolished within 7 h in 100% Dulbecco's compared with a mean of 24-31 h in other test solutions. At 12 h, burst frequency decreased faster in standard solution and 25% Dulbecco's (-0.28±0.07 and -0.13±0.05 bursts/h, respectively) compared with PBG solution (-0.09±0.04 bursts/h); amplitude declined at ∼2%/h in all solutions. The tendency for episodic discharge decreased gradually in standard solution, but was eliminated in 25% Dulbecco's and PBG solution. Certain bath solutions may minimize time-dependent frequency reductions but may also cause breathing pattern changes.
KW - Control of breathing, respiratory motor output
KW - Methods, respiratory motor output, bath solution
KW - Reptiles, red-eared slider turtle (Trachemys scripta)
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U2 - 10.1016/j.resp.2003.08.006
DO - 10.1016/j.resp.2003.08.006
M3 - Article
C2 - 14609514
AN - SCOPUS:0242438684
SN - 1569-9048
VL - 138
SP - 253
EP - 263
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 2-3
ER -