Zhou D, Wasicko M J, Hu J M, St John W M
Department of Physiology, Dartmouth Medical School, Hanover, New Hampshire 03756.
J Appl Physiol (1985). 1991 Mar;70(3):1265-70. doi: 10.1152/jappl.1991.70.3.1265.
Our purpose was to compare further eupneic ventilatory activity with that of gasping. Decerebrate, paralyzed, and ventilated cats were used; the vagi were sectioned within the thorax caudal to the laryngeal branches. Activities of the phrenic nerve and medullary respiratory neurons were recorded. Antidromic invasion was used to define bulbospinal, laryngeal, or not antidromically activated units. The ventilatory pattern was reversibly altered to gasping by exposure to 1% carbon monoxide in air. In eupnea, activities of inspiratory neurons commenced at various times during inspiration, and for most the discharge frequency gradually increased. In gasping, the peak discharge frequency of inspiratory neurons was unaltered. However, all commenced activities at the start of the phrenic burst and reached peak discharge almost immediately. The discharge frequencies of all groups of expiratory neurons fell in gasping, with many neurons ceasing activity entirely. These data are consistent with the hypothesis that brain stem mechanisms controlling eupnea and gasping differ fundamentally.
我们的目的是进一步比较平静呼吸时的通气活动和喘息时的通气活动。实验使用了去大脑、麻痹并进行通气的猫；在胸腔内喉部分支的尾端切断迷走神经。记录膈神经和延髓呼吸神经元的活动。采用逆向冲动入侵来确定延髓脊髓、喉部或非逆向激活的单位。通过在空气中暴露于1%的一氧化碳，通气模式可逆地转变为喘息。在平静呼吸时，吸气神经元的活动在吸气过程中的不同时间开始，并且对于大多数神经元来说，放电频率逐渐增加。在喘息时，吸气神经元的放电频率峰值未改变。然而，所有神经元均在膈神经爆发开始时开始活动，并且几乎立即达到放电峰值。在喘息时，所有呼气神经元组的放电频率均下降，许多神经元完全停止活动。这些数据与以下假设一致，即控制平静呼吸和喘息的脑干机制存在根本差异。
