CELLULAR AND BIOCHEMICAL-MECHANISMS UNDERLYING CIRCADIAN-RHYTHMS IN VERTEBRATES

Circadian clocks organize neural processes, such as motor activities, into near 24-hour oscillations and adaptively synchronize these rhythm s to the solar cycle. Recently, the first mammalian clock genes have b een found. Unpredicted diversity in signaling pathways and clock-contr olled gating of signals that modulate timekeeping has been discovered. A diffusible clock output has been found to control some behavioral r hythms. Consensus is emerging that circadian mechanisms are conserved across phylogeny, but that mammals have developed a great complexity o f controls.