Biology Reference
In-Depth Information
CHAPTER SIX
Control of Sleep and Wakefulness
in Health and Disease
*
Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, California, USA
†
Mental Illness Research Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto,
California, USA
Contents
1. The Brain Stem
138
2. The Hypothalamus
143
3. The Cortex
147
4. The Endocrine System
148
5. The Rest
149
References
150
Abstract
Sleep and wake are actively promoted states of consciousness that are dependent on a
network of state-modulating neurons arising from both the brain stem and hypothal-
amus. This network helps to coordinate the occurrence of a sleep state in billions of
cortical neurons. In many neurological diseases, there is a specific disruption to one
of the components of this network. Under conditions of such disruptions, we often gain
an improved understanding of the underlying function of the specific component
under nonpathological conditions. The loss or dysfunction of one of the hypothalamic
or brain stem regions that are responsible for promotion of sleep or wake can lead to
disruptions in sleep and wake states that are often subtle, but sometime quite pro-
nounced and of significant medical importance. By understanding the neural substrate
and its pathophysiology, one can more appropriately target therapies that might help
the specific sleep disruption. This chapter reviews what is currently understood about
the neurobiological underpinnings of sleep and wake regulation and how various
pathologies evoke changes in these regulatory mechanisms.
Sleep and wake in mammals are created by a complex confluence of multiple
neuromodulatory systems that push the brain into the various firing modes
that constitute our experience of “sleep” and “wake,” both of which are
actively generated states. These systems include those found in the brain
stem (serotonin, noradrenaline, acetylcholine, dopamine, glutamate),
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