Changes in cat medullary neurone firing rates and synchrony following induction of respiratory long-term facilitation.

摘要: 1. Long-term facilitation is a respiratory memory expressed as an increase in motor output lasting more than hour. This change induced by repeated hypoxia, stimulation of carotid chemoreceptors, or electrical the sinus nerve brainstem mid-line. The present work addressed hypothesis that persistent changes medullary neural networks contribute to long-term facilitation. 2. Carotid chemoreceptors were stimulated close arterial injection CO 2-saturated saline solution. Phrenic efferent activity and up 30 single neurones recorded simultaneously nucleus tractus solitarii (NTS) including dorsal group (DRG), Botzinger-ventral (Bot-VRG), raphe obscurus nine adult cats, anaesthetized, injected with neuromuscular blocking agent, vagotomized artificially ventilated. 3. firing rates 87 105 (83 %) changed following induction Nine eleven DRG Bot-VRG putative premotor inspiratory had increased Fourteen twenty-one control less 4 Hz significant increases activity. 4. Cross-correlogram analysis suggested there effective connectivity neuron pairs Joint peristimulus time histograms pattern detection methods used ‘gravity’ also detected short scale correlations associated 5. results suggest synchrony VRG altered among other functionally antecedent elements network expression