How Body Clocks Affect Brain Function and Behavior

Circadian rhythms in mammals are regulated by the suprachiasmatic nucleus (SCN), which synchronizes with environmental light:dark cycles.

• The SCN serves as the master circadian clock, influencing daily rhythms in behavior, physiology, and metabolism.
• Direct connections from the retina to the SCN allow it to adjust to changes in light conditions.
• The core mechanism involves a feedback loop where clock genes and their proteins regulate their own expression.
• This feedback loop interacts with additional loops to create specific 'circadian transcriptomes' in different tissues.
• Peripheral tissues send signals to the SCN, helping it adapt to the organism's internal state.

Simplified