Explain the role of the brain in sleep. - Scottish Highers Psychology - Question 1(a) - 2022

The brain plays a crucial role in regulating sleep and its various phases.

1. Adenosine Buildup: During wakefulness, adenosine—a neurotransmitter—accumulates in the brain. This buildup leads to the feeling of sleepiness, prompting the body to seek rest to restore energy levels.

2. Melatonin Production: The brain's pineal gland is responsible for synthesizing melatonin, especially during the dark hours. Melatonin regulates the sleep-wake cycle, signaling to the body when it is time to sleep and wake up.

3. Sleep Stages: The brain orchestrates distinct sleep phases, including REM (rapid eye movement) and NREM (non-rapid eye movement) sleep. Each phase has its own functions related to memory consolidation and physical recovery.

4. Suprachiasmatic Nucleus (SCN): The SCN, located in the hypothalamus, acts as the body's internal clock. It receives input from light and dark signals to help regulate the circadian rhythm, influencing the timing of sleep and wakefulness.

5. Pathway to the Pineal Gland: The SCN sends signals to the pineal gland, modulating melatonin production according to the external environment, which adjusts the sleep patterns based on natural light cycles.

In summary, the brain regulates sleep through the interplay of various neurotransmitters, specific glands, and innate biological rhythms, ensuring that the body achieves its restorative processes during sleep.