Berger A J, Herbert D A, Mitchell R A
Respir Physiol. 1978 Jun;33(3):323-7. doi: 10.1016/0034-5687(78)90059-2.
Reversible cold block of the rostral pons was used to compare properties of normal and apneustic respiration in anesthetized, vagotomized, artificially ventilated cats. During apneusis we observed high frequency oscillations (HFO) in phrenic nerve activity which were reduced in frequency compared with those during a normal inspiration. Apneusis produced by mid-pontine transection or punctate pneumotaxic center (PC) lesion produced similar HFO changes. The minimal intensity of superior laryngeal nerve electrical stimulation needed to terminate a breath was higher early in an apneusis than at the same time during a normal breath. Later in apneusis the intensity required became constant and was approximately the same as that needed to end a normal inspiration at its natural termination. With intact vagi lung inflation produced a greater prolongation of expiration during apneustic respiration than during normal respiration. Apneustic type activity was observed in both phrenic and vagal inspiratory motoneurons. We suggest that: (1) HFO are generated without the PC, but the PC elevates the oscillation frequency; and (2) apneusis may result in part from a delayed activation of the normal inspiratory off-switch mechanism.
采用可逆性阻断延髓脑桥前部的方法，对麻醉、切断迷走神经并进行人工通气的猫的正常呼吸和长吸式呼吸特性进行比较。在长吸式呼吸期间，我们观察到膈神经活动中的高频振荡（HFO），与正常吸气时相比，其频率降低。脑桥中部横断或点状损毁呼吸调整中枢（PC）所产生的长吸式呼吸，会产生类似的高频振荡变化。在长吸式呼吸早期，终止一次呼吸所需的喉上神经电刺激的最小强度，高于正常呼吸同期。长吸式呼吸后期，所需强度变得恒定，且与正常吸气自然终止时所需强度大致相同。迷走神经完整时，肺充气在长吸式呼吸期间比在正常呼吸期间能使呼气延长更多。在膈神经和迷走神经吸气运动神经元中均观察到长吸式呼吸类型的活动。我们认为：（1）高频振荡在没有呼吸调整中枢的情况下产生，但呼吸调整中枢会提高振荡频率；（2）长吸式呼吸可能部分源于正常吸气切断机制的延迟激活。
