Year-end Sale % OFF 
Abstract
Most physiological processes in our body oscillate in a daily fashion. These include cerebral activity (sleep-wake cycles), metabolism and energy homeostasis, heart rate, blood pressure, body temperature, renal activity, and hormone as well as cytokine secretion. The daily rhythms in behaviour and physiology are not just acute responses to timing cues provided by the environment, but are driven by an endogenous circadian timing system. A central pacemaker in the suprachiasmatic nucleus (SCN), located in the ventral hypothalamus, coordinates all overt rhythms in our body through neuronal and humoral outputs. The SCN consists of two tiny clusters of ~100,000 neurones in humans, each harbouring a self-sustained, cell-autonomous molecular oscillator. Research conducted during the past years has shown, however, that virtually all of our thirty-five trillion body cells possess their own clocks and that these are indistinguishable from those operative in SCN neurones. Here we give an overview on the molecular and cellular architecture of the mammalian circadian timing system and provide some thoughts on its medical and social impact.
Highlights
Owing to the rotation of the earth around its own axis all living beings are exposed to 24-hour light-dark and temperature cycles
In order for the suprachiasmatic nucleus (SCN) to stay in synchrony with the outside world, its circadian clocks must be readjusted every day by a few minutes
How do we know that the SCN is really the conductor of the clock orchestra? The most convincing demonstration comes from stereotaxic lesion and transplantation experiments between wildtype and tau mutant hamsters, which in constant darkness display locomotor activity rhythms with period lengths of 24 hours and 20 hours, respectively [3]
Summary
Most physiological processes in our body oscillate in a daily fashion. These include cerebral activity (sleep-wake cycles), metabolism and energy homeostasis, heart rate, blood pressure, body temperature, renal activity, and hormone as well as cytokine secretion. The daily rhythms in behaviour and physiology are not just acute responses to timing cues provided by the environment, but are driven by an endogenous circadian timing system. The SCN consists of two tiny clusters of ~100,000 neurones in humans, each harbouring a self-sustained, cell-autonomous molecular oscillator. We give an overview on the molecular and cellular architecture of the mammalian circadian timing system and provide some thoughts on its medical and social impact
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
