Biological Rhythms & Sleep: Brain Regions, Sleep Disorders, & Drugs that Affect Sleep

Made by @agreyr

How the brain controls sleep

1. Forebrain system that generates SWS

2. Brainstem system that activates the sleeping forebrain to wakefulness (reticular activating system of the brainstem)

3. Pontine system that triggers REM sleep (REM sleep nuclei in the pons)

4. Hypothalamic system that coordinates the others

Sleep disorders

Insomnia, hypersomnia, sleep apnea, unreliable respiration, nocturnal myoclonus, narcolepsy, nightmares, night terror, REM behavior disorder, sleep paralysis

Sleep apnea

Unreliable respiration

Nocturnal myoclonus

Restless leg syndrome

Nightmares vs night terror

Nightmares are frightening dreams; night terror is arousal from SWS, intense fear

Narcolepsy

Daytime sleep attacks, cataplexy, sleep hallucinations

REM behavior disorder

Act out a dream while sleeping

Sleep paralysis

Inability to talk/move upon waking or falling asleep

Drugs that affect sleep

Hypnotic drugs and anti-hypnotic drugs

Hypnotic drugs

Benzodiazepines, Ambien, Melatonin

Anti-hypnotic drugs

Stimulants and tricyclic antidepressants

Benzodiazepines

Hypnotic drug

Short-term effects: increase drowsiness, decrease time it takes to fall asleep, reduce number of awakenings, increase total sleep time

Chronic use not recommended; tolerance develops, cessation of use causes insomnia, chronic use causes addiction, they distort the normal pattern of sleep

Ambien

Hypnotic drug

FDA approved for short-term treatment of insomnia; non-benzodiazepine hypnotic but binds to the benzodiazepine site of GABA

Side effects: drowsiness, sleepiness, headache, dizziness, memory impairment, muscle and joint pain

Tolerance, dependance, and withdrawal are possible

Melatonin

Hypnotic drug; a hormone synthesized from serotonin in the pineal gland

Circulating levels of melatonin display circadian rhythms (SCN of the hypothalamus; highest levels associated with darkness and sleep, usefulness is disputable

Stimulants and tricyclic antidepressants

Increase activity of catecholamines by increasing release, blocking reuptake, or both

They act preferentially on REM sleep; can totally suppress REM sleep

Chronic use not recommended; highly addictive, adverse side effects, can interfere with normal sleep