Normal Sleep Patterns in Macaque Monkey

Abstract

<h3>Introduction</h3> THE PURPOSE of this paper is to attempt a more complete definition of the normal sleep pattern of the monkey<i>Macaca nemestrina</i>and to investigate the electrical activity of the cortex and various deep brain structures during sleep by means of the electroencephalogram and the averaged evoked response to a sound stimulus. The majority of neurophysiological studies on sleep during the last few years have been primarily concerned with the cat. Lately, however, there has arisen some evidence that certain differences exist between sleep in the cat and sleep in the subhuman primate,^1,25suggesting that, by phylogenetic affinities to man, other primates may assist materially in the elucidation of human sleep mechanisms. Extensive work has been carried out on the neurophysiology of sleep in the cat.^7,16,17,29The natural sleep of cats is divided by most observers into two basic stages.^7,22The first is one of