The differential organization of medullary post-inspiratory activities |
| |
Authors: | D W Richter D Ballantyne J E Remmers |
| |
Institution: | (1) Physiologisches Institut, Universität Heidelberg, Im Neuenheimer Feld 326, D-6900 Heidelberg, Federal Republic of Germany;(2) Pulmonary Division, University of Calgary, Department of Medicine, T2N 2T9 Calgary, Alta, Canada |
| |
Abstract: | Membrane potential trajectories of 68 bulbar respiratory neurones from the peri-solitary and peri-ambigual areas of the brain-stem were recorded in anaesthetized cats to explore the synaptic influences of post-inspiratory neurones upon the medullary inspiratory network.A declining wave of inhibitory postsynaptic potentials resembling the discharge of postpinspiratory neurones was seen in both bulbospinal and non-bulbospinal inspiratory neurones, including alpha- and beta-inspiratory, early-inspiratory, late-inspiratory and ramp-inspiratory neurones.Activation of laryngeal and high-threshold pulmonary receptor afferents excited bulbar post-inspiratory neurones, whilst in the case of inspiratory neurones such stimulation produced enhanced postsynaptic inhibition during the same period of the cycle. Activation of post-inspiratory neurones and enhanced post-inspiratory inhibition of inspiratory bulbospinal neurones was accompanied by supression of the after-discharge of phrenic motoneurones.These results suggest that a population of post-inspiratory neurones exerts a widespread inhibitory function at the lower brain-stem level. Implications of such an inhibitory function for the organization of the respiratory network are discussed in relation to the generation of the respiratory rhythm. |
| |
Keywords: | Medullary respiratory neurones Respiratory rhythm generation Post-inspiratory activity Pulmonary afferents Laryngeal afferents |
本文献已被 SpringerLink 等数据库收录! |
|