The hypothalamus, particularly the suprachiasmatic nucleus (SCN), is responsible for regulating circadian rhythms and sleep-wake cycles.

Serotonin is a neurotransmitter that plays a crucial role in regulating sleep. It promotes relaxation and helps initiate sleep.

Delta waves are high-amplitude, slow-frequency brain waves that are associated with deep sleep (stages 3 and 4 of NREM sleep).

The pons, specifically the pontine tegmentum, plays a crucial role in regulating REM sleep, including the generation of rapid eye movements and muscle atonia.

The temporal lobe, particularly the medial temporal lobe structures such as the hippocampus and amygdala, is involved in memory consolidation and emotional processing, which are thought to contribute to dreaming.

REM sleep is believed to play a crucial role in consolidating memories, particularly procedural and emotional memories.

GABA (gamma-aminobutyric acid) is the primary neurotransmitter responsible for inhibiting muscle activity during REM sleep, leading to muscle atonia.

REM saccades are the rapid, conjugate eye movements that occur during REM sleep and are thought to be related to visual imagery and dreaming.

Stage 2 sleep is characterized by the appearance of sleep spindles (brief bursts of high-frequency, low-amplitude waves) and K-complexes (sharp, transient waves).

Sleep onset latency refers to the time it takes to fall asleep from the moment you close your eyes.

Melatonin is a hormone produced by the pineal gland in response to darkness. It plays a crucial role in regulating the sleep-wake cycle and promoting sleep.

Sleep paralysis is a temporary inability to move or speak that occurs during the transition between sleep and wakefulness.

NREM (non-rapid eye movement) sleep is characterized by the absence of rapid eye movements and muscle atonia. It consists of stages 1, 2, 3, and 4.

Lucid dreaming is the ability to control and manipulate one's dreams while being aware that one is dreaming.

The thalamus is involved in the generation of sleep spindles, which are brief bursts of high-frequency, low-amplitude waves that occur during stage 2 sleep.