Open Access

The circadian clock in mammals

The Journal of Headache and PainOfficial Journal of the Italian Society for the Study of Headaches6:242

DOI: 10.1007/s10194-005-0242-6

The original article was published in The Journal of Headache and Pain 2000 1:103


The basic physiological and anatomical basis for circadian rhythms in mammalian behaviour and physiology is introduced. The pathways involved in photic entrainment of the circadian clock are discussed in relation of new findings that identify the molecules that are involved in signalling between the environment and the clock. The molecular basis of endogenous cycles is described in the mouse, and compared to the mechanism that is present in the fly. Finally we speculate on the relationship between circadian physiology and pain.

Key words

Molecular chronobiology Circadian Mammals Genes Cluster headache Pain