The Mammalian Circadian Timing System: Organization and Coordination of Central and Peripheral Clocks

Mammalian physiology and behavior typically follow daily oscillations influenced by a central circadian clock and environmental cues.

• The circadian timing system consists of a central pacemaker in the brain's suprachiasmatic nuclei (SCN) and subsidiary clocks in various body cells.
• Environmental factors, such as light intensity and temperature, help synchronize the SCN with geophysical time.
• The SCN affects circadian rhythms through neuronal and hormonal signals, influencing physiology and behavior.
• Local oscillators in most organs and tissues are synchronized by the SCN's output pathways, which also serve as input pathways for these tissues.
• Recent research has enhanced understanding of the intricate architecture and functions of the mammalian circadian timing system.

AI simplified