Xu F, Frazier D T
Department of Physiology, University of Kentucky, Lexington 40536, USA.
J Appl Physiol (1985). 1997 Apr;82(4):1177-84. doi: 10.1152/jappl.1997.82.4.1177.
Responses of cerebellar respiratory-related neurons (CRRNs) within the rostral fastigial nucleus and the phrenic neurogram to activation of respiratory mechano- and chemoreceptors were recorded in anesthetized, paralyzed, and ventilated cats. Respiratory challenges included the following: 1 ) cessation of the ventilator for a single breath at the end of inspiration (lung inflation) or at functional residual capacity, 2) cessation of the ventilator for multiple breaths, and 3) exposure to hypercapnia. Nineteen CRRNs having spontaneous activity during control conditions were characterized as either independent (basic, n = 14) or dependent (pump, n = 5) on the ventilator movement. Thirteen recruited CRRNs showed no respiratory-related activity until breathing was stressed. Burst durations of expiratory CRRNs were prolonged by sustained lung inflation but were inhibited when the volume was sustained at functional residual capacity; it was vice versa for inspiratory CRRNs. Multiple-breath cessation of the ventilator and hypercapnia significantly increased the firing rate and/or burst duration concomitant with changes noted in the phrenic neurogram. We conclude that CRRNs respond to respiratory inputs from CO2 chemo- and pulmonary mechanoreceptors in the absence of skeletal muscle contraction.
在麻醉、麻痹并进行通气的猫身上，记录了延髓顶核内小脑呼吸相关神经元（CRRNs）和膈神经图对呼吸机械感受器和化学感受器激活的反应。呼吸刺激包括以下几种：1）在吸气末（肺膨胀）或功能残气量时停止通气一次呼吸；2）停止通气多次呼吸；3）暴露于高碳酸血症。在对照条件下有自发活动的19个CRRNs被分为依赖呼吸机运动的独立型（基本型，n = 14）或依赖型（泵型，n = 5）。13个被募集的CRRNs在呼吸受到压力之前没有显示出与呼吸相关的活动。持续肺膨胀会延长呼气CRRNs的爆发持续时间，但当肺容量维持在功能残气量时则会受到抑制；吸气CRRNs则相反。多次呼吸停止通气和高碳酸血症会显著增加放电频率和/或爆发持续时间，同时膈神经图也会出现相应变化。我们得出结论，在没有骨骼肌收缩的情况下，CRRNs对来自二氧化碳化学感受器和肺机械感受器的呼吸输入有反应。
