Morrison A R
Acta Neurobiol Exp (Wars). 1979;39(6):567-83.
Our studies suggest that paradoxical sleep is a state in which the brainstem is in a functional mode normally associated with presentations of novel stimuli. Furthermore, the combination of atonia and an internal state of activation indicates sustained activity of a brainstem mechanism designed to dampen responses to sudden, novel stimuli in wakefulness lest the animal over react and run blindly into danger prior to stimulus analysis. This conclusion stems from two sets of data. Studies of large-amplitude waves, which characteristically occur spontaneously just prior to and during paradoxical sleep, have demonstrated that the waves are signs of alerting. These waves, termed ponto-geniculooccipital (PGO) spikes, can be induced during both slow wave and paradoxical sleep by external stimuli at a threshold below actual arousal. Whenever cats are confronted with novel stimuli during wakefulness, eye movement potentials, which are recorded from the same sites as PGO spikes but differ from them in several characteristics, assume all the characteristics of PGO spikes. These observations indicate that the central nervous system during paradoxical sleep is in a "peculiar" state of activation which is not behaviorally expressed. Other experiments have focused on the muscle atonia of paradoxical sleep. Small, bilateral dorsolateral pontine tegmental lesions create the dramatic phenomenon of paradoxical sleep without atonia which is characterized as follows: After slow wave sleep, when paradoxical sleep with muscle atonia would normally appear, cats raise their heads, make body righting movements, exhibit alternating movements of the limbs, and even attempt to stand. Throughout an episode, which shows all other aspects of paradoxical sleep, including unresponsiveness to visual stimuli, cats act as if they are being startled, searching and sometimes attacking an object. In wakefulness they show minor cerebellar signs. Presumably the lesions disrupt both the pontine excitation of the medullary inhibitory area and the inhibition of a brainstem system for mobilizing activity normally in force during paradoxical sleep. Studies of the same cats during wakefulness have shown that there in an increase in exploratory locomotor activity of 23 to 127 percent as measured in an open-field test. The existence of parallel effects on motor control in wakefulness and paradoxical sleep produced by pontine lesions suggests that the atonia of paradoxical sleep is a reflection of excessive activity of a brainstem response dampening mechanism which operates more subtly during wakefulness to produce appropriately modulated responses to various unexpected stimuli.
我们的研究表明，异相睡眠是一种脑干处于通常与新刺激呈现相关的功能模式的状态。此外，肌张力缺失与激活的内部状态相结合，表明脑干机制持续活动，该机制旨在抑制清醒时对突然的新刺激的反应，以免动物在刺激分析之前过度反应并盲目陷入危险。这一结论源于两组数据。对大振幅波的研究表明，这些波是警觉的迹象，大振幅波通常在异相睡眠之前及期间自发出现。这些波被称为脑桥-膝状体-枕叶（PGO）尖峰，在慢波睡眠和异相睡眠期间，低于实际觉醒阈值的外部刺激均可诱发。每当猫在清醒时面对新刺激时，从与PGO尖峰相同部位记录的眼动电位，虽然在几个特征上与PGO尖峰不同，但会呈现出PGO尖峰的所有特征。这些观察结果表明，异相睡眠期间中枢神经系统处于一种未在行为上表现出来的“特殊”激活状态。其他实验则聚焦于异相睡眠的肌张力缺失。双侧小的脑桥背外侧被盖部损伤会产生异相睡眠但无肌张力缺失这一显著现象，其特征如下：在慢波睡眠之后，当通常会出现伴有肌张力缺失的异相睡眠时，猫会抬起头，进行身体扶正动作，表现出四肢交替运动，甚至试图站立。在整个发作过程中，猫表现出异相睡眠的所有其他方面，包括对视觉刺激无反应，它们的行为就好像受到了惊吓、在搜索，有时还会攻击某个物体。在清醒状态下，它们表现出轻微的小脑体征。推测这些损伤破坏了延髓抑制区的脑桥兴奋以及在异相睡眠期间通常起作用的用于调动活动的脑干系统的抑制。对这些猫在清醒状态下的研究表明，在旷场试验中测量到的探索性运动活动增加了23%至127%。脑桥损伤在清醒和异相睡眠中对运动控制产生的平行效应表明，异相睡眠的肌张力缺失是脑干反应抑制机制过度活动的一种反映，该机制在清醒时更微妙地运作，以对各种意外刺激产生适当调节的反应。
