The body responds to variations in light independently of the brain

During the day, we experience a series of physical, mental and behavioural changes know as circadian rhythms. These changes are governed by a central clock, located in the hypothalamus, which lies in the centre of the brain. This clock is responsible for synchronizing our tissues to ensure that their functions are coordinated and that they work with the same clock.

Scientists at the Institute for Research in Biomedicine (IRB Barcelona) have revealed that although each tissue receives information from the central clock in order to coordinate its functions, each one also has the capacity to respond independently to variations in light and to detect changes in light intensity between the day and night.

Published in two papers in the journal Cell, the studies confirm that this autonomy allows tissues to maintain minimal functions even when another tissue in our body is failing. “The results of these studies are likely to be particularly relevant during aging and in diseases in which high tissue interdependence would lead to a general deterioration of the organism,” says Salvador Aznar Benitah, head of the Stem Cells and Cancer Laboratory at IRB Barcelona.

Until now, there was no suitable animal model in which to test whether the clock regulating all our organs and tissues is coordinated by the brain or, as has been observed, whether these organs and tissue are capable of responding directly to the cyclic environmental changes that occur every day. This study, which has been conducted by IRB Barcelona, in collaboration with Paolo Sassone-Corsi’s team at the University of California, Irvine (US), has been possible thanks to a new mouse model that has allowed researchers to isolate the communication of each tissue from the rest.

Source: The body responds to variations in light between the day and night independently of the brain