Aging clocks: disrupted circadian rhythms

The earth’s rotation around its very own axis generates the phenomenon that we refer to as our day and night. This change in environmental lighting has been an essential component of life; where throughout the evolutionary chain, organisms have used this signal as a timing cue to which they regulate/ synchronise their sleep-wake activity. It is this entrainment of both phy- siological processes and behavioural traits that define and, in some aspects, govern an individual’s life style through circadian linked routines. Mammals, are no exception to this rule, often being referred to as ’creatures of habit’. From inception through to old age humans tend to gravitate to structured and defined periodic sleep- wake patterns; an uncanny system innately programmed into every individual, contributing to good health and wellbeing. However, the caveat lies within the aging process itself. Aging of the physio- logical components that govern and maintain circadian rhythms in mammals result in disruption to the clock leading to problems in sleep, cognition and social function, to name but a few. Little is known regarding the underlying mechanisms driving such changes; thus, it is imperative that we understand the natural biological aging process so to develop therapies and treatments that improve the quality of life in our, ever growing, aging population.