Silvani Alessandro
Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
Temperature (Austin). 2017 Feb 16;4(2):128-140. doi: 10.1080/23328940.2017.1295128. eCollection 2017.
This brief review aims to provide an updated account of the cardiovascular events of awakening, proposing a testable conceptual framework that links these events with the neural control of sleep and the autonomic nervous system, with focus on the hypothalamic orexin (hypocretin) neurons. Awakening from non-rapid-eye-movement sleep entails coordinated changes in brain and cardiovascular activity: the neural "flip-flop" switch that governs state transitions becomes biased toward the ascending arousal systems, arterial blood pressure and heart rate rise toward waking values, and distal skin temperature falls. Arterial blood pressure and skin temperature are sensed by baroreceptors and thermoreceptors and may positively feedback on the brain wake-sleep switch, thus contributing to sharpen, coordinate, and stabilize awakening. These effects may be enhanced by the hypothalamic orexin neurons, which may modulate the changes in blood pressure, heart rate, and skin temperature upon awakening, while biasing the wake-sleep switch toward wakefulness through direct neural projections. A deeper understanding of the cardiovascular events of awakening and of their links with skin temperature and the wake-sleep neural switch may lead to better treatments options for patients with narcolepsy type 1, who lack the orexin neurons.
本简要综述旨在提供关于觉醒时心血管事件的最新阐述，提出一个可检验的概念框架，将这些事件与睡眠的神经控制及自主神经系统联系起来，重点关注下丘脑食欲素（下丘脑泌素）神经元。从非快速眼动睡眠中觉醒需要大脑和心血管活动的协调变化：控制状态转换的神经“双稳态”开关偏向上升性唤醒系统，动脉血压和心率朝着清醒时的值上升，远端皮肤温度下降。压力感受器和温度感受器感知动脉血压和皮肤温度，并可能对大脑的觉醒 - 睡眠开关产生正反馈，从而有助于使觉醒更加敏锐、协调和稳定。下丘脑食欲素神经元可能会增强这些效应，其可能调节觉醒时血压、心率和皮肤温度的变化，同时通过直接神经投射使觉醒 - 睡眠开关偏向清醒状态。对觉醒时心血管事件及其与皮肤温度和觉醒 - 睡眠神经开关之间联系的更深入理解，可能会为缺乏食欲素神经元的1型发作性睡病患者带来更好的治疗选择。
