Bremer F
Ann Neurol. 1977 Jul;2(1):1-6. doi: 10.1002/ana.410020102.
Active cerebral processes can initiate and maintain sleep in mammals. Two distinct hypnogenic structures have been documented in the cat: the nucleus of the solitary tract in the medulla and a region in the basal preoptic area. Their electrical or pharmacological activation results in behavioral and EEG sleep. Both can be activated an inhibited in relation to circulatory or thermic homeostasis and to endocrine regulations, or in conditioned paradigms. Bilateral destruction or functional elimination of either hypnogenic region is followed by increased vigilance and insomnia. The tonic influence so revealed is increased by the serotonergic raphe nuclei of the pontine region, which is considered to be hypnotonic rather than hypnogenic. Postsynaptic inhibition of the ascending activating reticular system by the hypnogenic centers is involved in sleep onset and maintenance. Electrophysiological evidence is presented that indicates a mutual tonic inhibitory interaction between the brainstem arousal system and the preoptic hypnogenic center. Such reciprocal inhibitory interaction can facilitate the onset of sleep by a positive-feedback mechanism. In spite of the fact that this retroaction results in break of physiological equilibrium, it should be considered a homeostatic process aimed at maintaining the functional fitness of the forebrain neuronal circuits.
活跃的大脑活动过程能够启动并维持哺乳动物的睡眠。在猫身上已记录到两种不同的促眠结构：延髓中的孤束核以及视前区基底的一个区域。对它们进行电刺激或药物刺激会导致行为睡眠和脑电图睡眠。在与循环或热稳态、内分泌调节相关的情况下，或者在条件范式中，这两种结构都能够被激活或抑制。双侧破坏或功能性消除任何一个促眠区域都会导致警觉性增加和失眠。如此揭示出的紧张性影响会被脑桥区域的5-羟色胺能中缝核增强，该中缝核被认为具有催眠作用而非促眠作用。促眠中枢对上行激活网状系统的突触后抑制参与了睡眠的起始和维持。文中给出了电生理学证据，表明脑干觉醒系统和视前促眠中枢之间存在相互的紧张性抑制相互作用。这种相互抑制相互作用能够通过正反馈机制促进睡眠的起始。尽管这种反馈作用会导致生理平衡的打破，但它仍应被视为一个旨在维持前脑神经元回路功能适应性的稳态过程。
