Current understanding on the neurobiology of sleep and wakefulness

Abstract

The modern concept of sleep and wakefulness has evolved from the landmark discovery of ascending reticular activating system by Moruzzi and Magoun in 1949. The other major contributions have come from the electrophysiological studies of sleep-wake states following the discovery of electroencephalogram by Hans Berger in 1929. Research studies over the past 60 years have provided us an enormous understanding on the neural basis of sleep-wake states and their regulatory mechanisms. By shuttling through the two behavioral states of sleep and wake, brain coordinates many complex functions essential for cellular homeostasis and adaptation to environment. This review briefly summarizes the current awareness on the dynamicity of brain mechanisms of sleep and wakefulness as well as the newer concepts of the biological functions of sleep.