Brain complexity: circadian controls in other organs (Introduction)

by David Turell , Tuesday, June 04, 2019, 18:48 (1999 days ago) @ dhw

It seems our internal organs have their own circadian clocks independent of the brain clock:

https://medicalxpress.com/news/2019-05-body-day-night-independently-brain.html

"Can your liver sense when you're staring at a television screen or cellphone late at night? Apparently so, and when such activity is detected, the organ can throw your circadian rhythms out of whack, leaving you more susceptible to health problems.

"That's one of the takeaways from two new studies by University of California, Irvine scientists working in collaboration with the Institute for Research in Biomedicine in Barcelona, Spain.

"The studies, published today in the journal Cell, used specially bred mice to analyze the network of internal clocks that regulate metabolism. Although researchers had suspected that the body's various circadian clocks could operate independently from the central clock in the hypothalamus of the brain, there was previously no way to test the theory, said Paolo Sassone-Corsi, director of UCI's Center for Epigenetics and Metabolism and senior author of one of the studies.

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"'The results were quite surprising," said Sassone-Corsi, Donald Bren Professor of Biological Chemistry. "No one realized that the liver or skin could be so directly affected by light."
For example, despite the shutdown of all other body clocks, including the central brain clock, the liver knew what time it was, responded to light changes as day shifted to night and maintained critical functions, such as preparing to digest food at mealtime and converting glucose to energy.

"Somehow, the liver's circadian clock was able to detect light, presumably via signals from other organs. Only when the mice were subjected to constant darkness did the liver's clock stop functioning.

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"In earlier studies, Sassone-Corsi has examined how circadian clocks can be rewired by such factors as sleep deprivation, diet and exercise. Exposure to computer, television or cellphone light just before bed can also scramble internal clocks.

"Because of modern lifestyles, it's easy for people's circadian systems to get confused, he said. In turn, that can lead to depression, allergies, premature aging, cancer and other health problems. Further mice experiments could uncover ways to make human internal clocks "less misaligned," Sassone-Corsi added. "

Comment: It is obvious that our bodies had to adapt to a 24-hour day during evolution to function properly at different times of activity, sleep, eating, etc. Chance development would have created confusion in functions, in a trail and error attempt. Only design fits.