Role of Cholinergic Mechanisms in States of Wakefulness and Sleep

Abstract

Publisher Summary Pharmacological data on the importance of cholinergic mechanisms in electroencephalogram (EEG) activation and behavioral arousal as well as sleep are impressive. The gross behavioral consequence of the initial EEG activation is clearly a wake-up or arousal state. This chapter summarizes some research on the hypothesis that cholinergic mechanisms are involved in states of wakefulness and sleep. It has previously been reported by Wikler, Bradley and Elkes, Bradley and Nicholson, and others, that cholinergic agonists and antagonists produce EEG dissociation from gross behavior. Similar findings have been made by us using large doses of atropine and physostigmine. However, it should be pointed out that effective doses of physostigmine and other cholinergic agonists produce initial behavioral arousal that is associated with neocortical and limbic activation. The emphasis in the literature on EEG dissociation from gross behavior may have been overstated, particularly in relationship to the awake–sleep cycle of the chronic cat. The findings of Bradley and Elkes and others with cholinergic agonists were made at a time when the stage of fast wave sleep as described by Dement and Jouvet was not generally known. It would appear that in some instances investigators may have been observing fast wave sleep and did not recognize it as such.