Control and role of brain clocks outside the main circadian center

Circadian clocks evolved in most organisms to adapt to 24-hour environmental changes.

• Circadian clocks are internal mechanisms that help organisms respond to daily environmental variations.
• The mammalian circadian clock system consists of cellular oscillators in all body tissues, organized hierarchically.
• A master pacemaker in the suprachiasmatic nucleus (SCN) coordinates the timing of peripheral tissue clocks.
• Various external cues, known as Zeitgebers, can reset the circadian clock system through the SCN or directly at the tissue level.
• Non-SCN brain oscillators, which are less studied, are influenced by the SCN and may have unique physiological roles.
• Understanding extra-SCN oscillators could provide insights into the overall organization of the circadian clock network in the brain.

Simplified