Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.
Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
Curr Neurol Neurosci Rep. 2020 Oct 2;20(12):55. doi: 10.1007/s11910-020-01075-x.
Melanin-concentrating hormone (MCH)-expressing neurons located in the lateral hypothalamus are considered as an integral component of sleep-wake circuitry. However, the precise role of MCH neurons in sleep-wake regulation has remained unclear, despite several years of research employing a wide range of techniques. We review recent data on this aspect, which are mostly inconsistent, and propose a novel role for MCH neurons in sleep regulation.
While almost all studies using "gain-of-function" approaches show an increase in rapid eye movement sleep (or paradoxical sleep; PS), loss-of-function approaches have not shown reductions in PS. Similarly, the reported changes in wakefulness or non-rapid eye movement sleep (slow-wave sleep; SWS) with manipulation of the MCH system using conditional genetic methods are inconsistent. Currently available data do not support a role for MCH neurons in spontaneous sleep-wake but imply a crucial role for them in orchestrating sleep-wake responses to changes in external and internal environments.
位于下丘脑外侧的黑色素聚集激素 (MCH) 表达神经元被认为是睡眠-觉醒回路的一个组成部分。然而，尽管采用了多种技术进行了多年的研究，MCH 神经元在睡眠-觉醒调节中的精确作用仍不清楚。我们回顾了这方面的最新数据，这些数据大多不一致，并提出了 MCH 神经元在睡眠调节中的新作用。
虽然使用“功能获得”方法的几乎所有研究都显示快速眼动睡眠（或异相睡眠；PS）增加，但功能丧失方法并未显示 PS 减少。同样，使用条件遗传方法对 MCH 系统进行操作时，报告的觉醒或非快速眼动睡眠（慢波睡眠；SWS）变化也不一致。目前可用的数据不支持 MCH 神经元在自发睡眠-觉醒中的作用，但暗示它们在协调对外部和内部环境变化的睡眠-觉醒反应方面起着至关重要的作用。
