The effects of microstimulation and microlesions in the ventral and dorsal respiratory groups in medulla of cat.

摘要: The responses in respiratory outflow resulting from microstimulation and successive microlesions of the dorsal (DRG) ventral (VRG) groups neurons brainstem were studied anesthetized, paralyzed, artificially ventilated cats. Microstimulation (2 to 120 Hz; 5 50 microA; 100 musec pulse duration) at almost every point within DRG or VRG produced a bilateral short latency inhibition phrenic nerve activity which had an onset 4 9 msec duration 24 msec. This global stereotyped was elicited by single pulses often accompanied postinhibitory excitation. In 48% (92/193) stimulation trials, trains stimulus during inspiration decreased inspiration. 25% expiratory increased 11%, expiration shortened markedly pulses. Single shocks delivered right excitation ipsilateral recurrent laryngeal (RRL). RRL 2 3 15 Evidence suggests that is due paucisynaptic activation motoneurons caudal VRG. synchronous with inspiratory Despite powerful effects DRG, extensive destruction these neuronal populations only modest on rhythm, while it (or abolished) nerves. combined results microlesion portions this study suggest region regions) outside might be important control pattern are determining depth inspiration; their role generating rhythm needs critically re-examined.