Circadian oscillators in thirst and hunger centers of the brain
Hugh PIGGINS
University of Bristol, UK
Invited by Etienne Challet
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, Hugh Piggins will present recent findings indicating that thirst centers 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.
Selected publications
- Keeping time in the lamina terminalis: Novel oscillator properties of forebrain sensory circumventricular organs. Northeast RC, Chrobok L, Hughes ATL, Petit C, Piggins HD. FASEB J. 2020 Jan;34(1):974-987.
- The Kidney Clock Contributes to Timekeeping by the Master Circadian Clock. Myung J, Wu MY, Lee CY, Rahim AR, Truong VH, Wu D, Piggins HD, Wu MS. Int J Mol Sci. 2019 Jun 5;20(11).
- Circadian Disruptions in the Myshkin Mouse Model of Mania Are Independent of Deficits in Suprachiasmatic Molecular Clock Function. Timothy JWS, Klas N, Sanghani HR, Al-Mansouri T, Hughes ATL, Kirshenbaum GS, Brienza V, Belle MDC, Ralph MR, Clapcote SJ, Piggins HD. Biol Psychiatry. 2018 Dec 1;84(11):827-837.
- Delayed Cryptochrome Degradation Asymmetrically Alters the Daily Rhythm in Suprachiasmatic Clock Neuron Excitability. Wegner S, Belle MDC, Hughes ATL, Diekman CO, Piggins HD. J Neurosci. 2017 Aug 16;37(33):7824-7836.
- Contributions of the lateral habenula to circadian timekeeping. Baño-Otálora B, Piggins HD. Pharmacol Biochem Behav. 2017 Nov;162:46-54.
- Circadian regulation of mouse suprachiasmatic nuclei neuronal states shapes responses to orexin. Belle MD, Piggins HD. Eur J Neurosci. 2017 Mar;45(5):723-732.
- Distinct roles for GABA across multiple timescales in mammalian circadian timekeeping. DeWoskin D, Myung J, Belle MD, Piggins HD, Takumi T, Forger DB. Proc Natl Acad Sci U S A. 2015 Jul 21;112(29):E3911-9.
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Organized by
Comité d'Animation et de Communication Scientifique de l'INCI
Marie-Pierre Laran-Chich, Etienne Challet, Sylvain Hugel & Stéphane Gasman
