The crucial role of cAMP and calcium signals in keeping the mammal body clock

Daily rhythms are fundamental to eukaryotic organisms, influencing metabolism, physiology, and behavior.

• Circadian rhythms allow organisms to anticipate and synchronize with daily environmental cycles.
• The master regulator of circadian timekeeping in mammals is located in the hypothalamic suprachiasmatic nucleus (SCN).
• Molecular models of circadian rhythms have traditionally emphasized transcriptional-translational feedback loops.
• Recent findings indicate that intracellular signaling mechanisms significantly contribute to timekeeping.
• cAMP and Ca2+ signaling are regulated by the cellular clock and directly influence pacemaker properties like amplitude, phase, and period.
• Daily auto-amplification of second messenger activity may enhance the accuracy and robustness of SCN timekeeping.

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