Neural Mechanisms of Sleep Apnea

在氟烷麻醉下，在锁骨前-乳房后水平对动物进行去脑。将玻璃绝缘钨微电极插入脑桥正中背被。对DTF区进行紧张性电刺激，证实刺激效果。DTF刺激引起体位张力和呼吸同时抑制。然后将另一个微电极插入喙侧脑桥网状结构，并用于记录功能。DTF以每秒一次的速度被刺激，并在桥的吻侧中识别出了逆行激活的神经元。逆行激活的神经元位于口桥网状核（PoO）。这些神经元几乎没有自发放电。在脑桥周围或附近的脑桥网状结构中微量注射一种胆碱能激动剂，可导致体位张力和呼吸的平行抑制，其效果与DTF刺激引起的效果非常相似。Hobson等人报告说，在慢性猫的便便中注射乙醇会导致动物进入快速眼动睡眠。我们已经阐明，存在一个下行抑制通路负责全身性运动抑制。该通路起始于大脊髓区神经元，经DTF区下行至脊髓。这些结果提示，本研究中发现的抑制系统可能在睡眠期间，特别是在快速眼动睡眠期间，其活动增加，并可能在中枢神经敏感性受损时导致睡眠呼吸暂停。

Under halothane anesthesia, the animal was decerebrated at the precollicular-postmammillary level. The glass-insulated tungsten microelectrode was inserted into the midpontine dorsal tegmentum (DTF). Tonic electrical stimulation was delivered to the DTF area, and the stimulus effects were confirmed. DTF stimulation evoked simultaneous suppression of postural tone and respiration. The another microelecrode was then inserted into the rostral pontine reticular formation, and was used for a recording function. DTF was stimulated at once per second, and the antidromically activated neurons were identified within the rostral pons. The antidromically activated neurons were located in the nucleus reticularis pontis oralis (PoO). Such neurons had little spontaneous discharges. A microinjection of carbachol, a cholinergic agonist, into the pontine reticular formation around or near the PoO resulted in the parallel suppression of postural tone and respiration, and the effects were very similar to those elicited by DTF stimulation. Hobson et al. reported that a carbachol injection into the PoO have led the animal to a REM sleep in chronic cats. We have already clarified that there exists a descending inhibitory pathway responsible for generalized motor suppression. The pathway originates from the neurons in the PoO and descends to the spinal cord via DTF area. All these findings lead us to suggest that the inhibitory system identified in this study may raise its activity during sleep, especially during REM sleep, and may result in the sleep apnea when the central chmosensitivity is damaged.