Nitric oxide modulates respiratory-related neural activity in the isolated brainstem of the bullfrog.
The effects of nitric oxide (NO) on respiratory-related neural activity were investigated using the isolated brainstem preparation from bullfrogs (Rana catesbeiana). Addition of the NO donor, sodium nitroprusside (SNP), or the amino acid precursor for NO synthesis, L-arginine (L-Arg), produced significant increases in respiratory-related burst frequency. Inhibition of nitric oxide synthase (NOS) with N(omega)-nitro-L-arginine (L-NA), a non-selective NOS inhibitor, 7-nitro indazole (7-NI), reversibly abolished burst activity. These results suggest that production of NO, probably via neuronal NOS (nNOS), provides a facilitatory input to the respiratory central pattern generator (CPG) in the amphibian brainstem. Endogenous production of NO may be a necessary inter- or intracellular messenger for neurotransmission and/or neuromodulation of central respiratory drive to motor effectors in the bullfrog.
Hedrick
M S
MS
Department of Biological Sciences, California State University, Hayward 94542, USA. mhedrick@.csuhayward.edu
Morales
R D
RD
Parker
J M
JM
Pacheco
J L
JL
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D011892:Rana catesbeiana; D012143:Respiratory Physiological Phenomena
D009569:Nitric Oxide