Timing - Understanding Central and Peripheral Clocks

From the discovery of the first clock genes outside of the ‘master clock’ – the suprachiasmatic nucleus (SCN) – to now, there has been extensive research into the location of these peripheral clocks and how they relate to the SCN and other timing signals. The purpose of this review is to provide an overview of the current knowledge in this area. Areas discussed will include: How the timing of sleep and wake in mammals is controlled by the central clock; how physiological processes during sleep and wake in mammals are coordinated by peripheral clocks; what changes in environmental signals affect the timing of SCN and peripheral clocks; how we measure central and peripheral clock timing; which environmental signals can entrain the SCN and peripheral clocks; and how disturbances in central and peripheral clock timing due to aspects of modern lifestyles including shiftwork and jet lag, as well as biological aspects such as blindness and chronotype, may have negative impacts on our health. By understanding how our biological timing systems work, we may be able to develop strategies to minimise disturbances in central and peripheral clock timing and therefore the associated negative health outcomes observed.