The states of sleep
Michel Jouvet
Scientific American (1967)


Brain Activities in Sleep

The Two Sleep States

The Suppression of Wakefulness

Sleep Centers

Paradoxical Sleep

The Evolution of Sleep

The Chemistry of Sleep


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Figure 7

BRAIN STRUCTURES involved in light sleep include the raphe system, which, by producing the monoamine serotonin, serves to counteract the alerting effects of the brain's reticular formation ("a," color at left). The author suggests that other nearby structures act to modulate the fast wave pattern of the alert cortex into the slower pattern typical of light sleep. Such slow activity, however, is known to depend on higher as well as lower brain structures (b); when a cat is deprived of its cerebral cortex and thalamus, the wave pattern characteristic of light sleep disappears. The reason for this is not yet understood.

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