Neural Mechanisms of Sleep Apnea

在氟烷麻醉下，动物在前丘-后乳头水平去脑。将玻璃绝缘钨微电极插入脑桥中背侧被盖（DTF）。对DTF区进行强直性电刺激，并证实刺激效果。DTF刺激引起的姿势性紧张和呼吸的同时抑制。另一个微电极插入脑桥头端网状结构，用于记录功能。以每秒一次的速度刺激DTF，在脑桥的嘴侧识别出逆向激活的神经元。逆向激活的神经元位于脑桥口侧网状核（PoO）。这些神经元几乎没有自发放电。微量注射卡巴胆碱，胆碱能激动剂，到脑桥网状结构周围或附近的PoO导致并行抑制姿势性紧张和呼吸，和DTF刺激引起的效果非常相似。霍布森等人报道，在慢性猫中，将卡巴胆碱注射到PoO中导致动物进入REM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。该通路起源于PoO内的神经元，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REM睡眠期间增强其活性，并可能在中枢化学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.