Hypoxia-induced short-term potentiation of respiratory-modulated facial motor output in the rat.

Abstract

Respiratory-modulated facial (VII) nerve discharge includes pre-inspiratory (Pre-I) and inspiratory (I) components. Tonic VII bursting is also present across the respiratory cycle. We tested the hypothesis that hypoxia-induced plasticity of VII motor activity is differentially expressed in Pre-I, I and tonic bursting. Phrenic and VII neurograms were recorded in urethane-anesthetized, vagotomized and ventilated adult rats. A 3 min isocapnic hypoxic challenge (PaO(2)=33+/-2 mmHg) was used to evoke respiratory short-term potentiation (STP). Pre-I, I and tonic VII activity increased immediately at the initial stage of hypoxia (i.e. acute response) and then progressively increased as hypoxia was maintained. Following hypoxia, I VII activity remained elevated (i.e. post-hypoxia STP) but both Pre-I and tonic activity immediately returned to baseline values. We conclude that STP following hypoxia is preferentially expressed in I compared to Pre-I and tonic VII activity.

DOI: 10.1016/j.resp.2010.06.015

Cite this paper

@article{Lee2010HypoxiainducedSP, title={Hypoxia-induced short-term potentiation of respiratory-modulated facial motor output in the rat.}, author={Kun-Ze Lee and D D Fuller}, journal={Respiratory physiology & neurobiology}, year={2010}, volume={173 1}, pages={107-11} }