Daily rhythm genes in organs outside the brain in mammals

Mammalian clock genes are expressed in a circadian manner throughout the body.

• The suprachiasmatic nucleus (SCN) in the hypothalamus was traditionally viewed as the sole controller of circadian rhythms in peripheral tissues.
• Peripheral cells possess circadian clocks similar to those in SCN neurons, although they are not self-sustained.
• Humoral signals may play a crucial role in synchronizing peripheral clocks with the central SCN clock.
• Conditions like restricted feeding can uncouple peripheral clocks from the central clock, allowing for adaptation to conflicting cues.
• The mechanisms by which circadian clocks regulate the expression of clock-controlled genes are still not fully understood.

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