The Time of our Lives: Ageing, and the Circadian Clock
Daily patterns in physiological, behavioural and cognitive processes are gated by an internal timekeeping mechanism. This pacemaker allows an organism to synchronise complex physiology within itself, and time this with respect to the environment. Disruption to synchronization has consequences as it is an independent risk factor for obesity, metabolic syndrome, cancer and depression. We have investigated ageing and clock function on a number of levels from the activity patterns of rodents, to the input pathways of environmental synchronising stimuli, to the actual cells that make up the clock. Monitoring the clock both in vivo and in vitro, we have found several age related changes in circadian clock function. We have also investigated strategies to improve synchronization in older animals. Finally we will discuss data from our human work to begin to see how the information gained from animal studies can be applied in the human population. Difficulty sleeping is one of the main reasons why people over the age of 65 visit their GP. The internal body clock contributes to the control of sleep duration, timing, and value. It is hoped that our work will lead to improved recommendations to improve circadian clock function in the aged.