Sleep and biological rhythms are the topics of Chapter 8. The opening chapter section describes the behavioral and electrophysiological changes that occur during the various stages of sleep. The second chapter section considers current theories of the "why" of sleep. Included are notions that sleep is an adaptive response that minimizes predation, that sleep is a restorative process, and that sleep is related to thermoregulation. The third chapter section describes the chemical and neural control of sleep and arousal. The fourth section provides information on sleep disorders including insomnia, disorders of REM sleep and disorders of slow-wave sleep. The final section of Chapter 8 covers issues related to biological clocks including a description of circadian rhythms, neural and hormonal controls of rhythms, and the disruption of these rhythms in shift-work and jet lag.

After completing the chapter, each student should be able to:

• Differentiate the two basic patterns of EEG recorded in an awake human.
• Describe the changes in EEG wave pattern recorded during sleep.
• Describe the evidence suggesting the existence of a 90-minute basic rest-activity cycle in humans.
• Differentiate between REM and slow-wave sleep.
• Contrast the mental activity reported in REM sleep and slow-wave sleep.
• Explain the hypothesis that sleep is an adaptive behavior.
• Explain the hypothesis that argues that sleep is a restorative process.
• Describe the effects of sleep deprivation in rats.
• Describe the relation between body temperature and sleep.
• Explain the changes in REM sleep that occur after sleep deprivation.
• Enumerate the four hypotheses as to the nature of REM sleep.
• Explain the significance of the observations made of sleep in dolphin brain for chemical theories of sleep.
• Describe evidence linking neurotransmitters in the brain to arousal.
• Define PGO waves.
• Describe the evidence linking ACh neurons to REM sleep.
• Explain why sleeping medication can be considered a cause for insomnia.
• Differentiate between insomnia and sleep apnea.
• Describe the four major symptoms of narcolepsy including:
• Sleep attack
• Catalepsy
• Sleep paralysis
• Hypnagogic hallucinations
• Describe the characteristics of REM with atonia.
• Describe three behaviors that can accompany slow-wave sleep.
• Define circadian rhythm.
• Name the brain structure that is the primary biological clock of the rat.
• Describe the evidence suggesting that SCN cells each contain a clock.
• Explain how the pineal gland may control seasonal rhythms.
• Explain how jet lag and shift-work represent problems with circadian rhythms.
• Explain how light and melatonin can be used to treat jet lag.