A riot of rhythms: Circadian clocks throughout the brain

Abstract

Circadian or intrinsic 24h rhythms pervade all aspects of our physiology and behavior and shape when we wake, eat, and sleep. They also influence our problem-solving abilities, memory formation, and athletic performance. These rhythms are generated by the master clock in the brain’s the suprachiasmatic nuclei or SCN.  Here the intracellular molecular clock drives SCN neurons to vary their electrical activity and to orchestrate rhythmic changes in brain and body. Intriguingly, rhythmic clock gene expression also occurs in other brain sites, but whether these are autonomous or dependent on SCN input is unclear. In this talk, I will present recent findings indicating that thirst centres as well as brainstem nuclei implicated in energy balance and cardiovascular control exhibit circadian rhythms in gene expression and neuronal activity that do not depend on the SCN. Further, preliminary evidence that the function of these structures is influenced by circadian mechanisms will be shown.  These findings raise the possibility that circadian control in the brain is devolved to local oscillators, thus challenging the ‘uni-clock’ model of the circadian system.

Bio

Hugh Piggins received a BSc in Experimental Psychology from the University of Edinburgh in 1985. He then worked as a research assistant in cognitive science at the University of Guelph in Canada before embarking on doctoral studies in behavioural effects of neuropeptides at the University of Ottawa.  Following his PhD, he obtained successive research fellowships to study the neural basis of circadian rhythms in the laboratories of Prof. Ben Rusak and Kazue Semba at McMaster and Dalhousie Universities. He returned to the UK in 1996 to a lectureship at King’s College London and then subsequently to the University of Manchester where he became of Professor of Neuroscience. His lab has used a range of approaches to study the organisation of circadian clocks in throughout the brain.  In 2019, he moved to the University of Bristol where he is Head of School for Physiology, Pharmacology, and Neuroscience.