Professor Andrew Loudon (BA, PhD, FSB, FMedSci) - research
Biological Clocks, Reproductive Biology, Molecular Endocrinology
The brain of all vertebrates contains a circadian clock, driving daily rhythms of behaviour, physiology and the neuroendocrine system. Systems as diverse as hibernation, seasonal reproduction and fattening cycles, daily activity and feeding cycles and sleep-wake rhythms are all driven via output from the circadian clock, entrained by light via specialised neural pathways. We are interested in how clocks time physiology and behaviour. We use both transgenic mice and seasonally breeding rodents (Syrian and Siberian hamsters) as model animals. We also work on larger model animals, including sheep (studies of melatonin action) and reindeer (studies of adaptations of arctic animals). Laboratory techniques we use include the generation of transgenic mice, cDNA array technologies, brain and cellular imaging using transgenic mouse models, gene expression studies and extensive behavioural and physiological monitoring methodologies.
Current work capitalises on the opportunities presented by the discovery of a single gene mutation (tau gene) of the biological clock in the Syrian hamster, causing the daily circadian clock to be driven at a faster rate, (20 vs 24h) and driving the neuroendocrine system at an accelerated rate. This unique model allows us to gain important insight into the way neural clocks couple with the neuroendocrine system. For part of this work, we are now using mice, and have recently developed new mouse transgenic models to study clock function in the brain (see Meng et al 2008).
The Siberian hamster exhibits remarkable adaptations to cope with life in seasonal environments, including the onset of torpor in winter. We are studying the seasonal clock in this species and how it regulates metabolism and reproduction. Recently, we have initiated studies on low temperature biology (torpor) and gene changes in the heart and other body organs, using array methods. Our approach is truly "Integrative" as we combine whole-organism studies of physiology and behaviour with genome-based technologies for investigating the cellular and genetic basis of adaptation to the environment. We have a major commitment to unravelling how melatonin acts to regulate neuroendocrine pathways.