We better understand the link between depression and the lack of natural light
Scientists already knew that a greater or lesser daylight exposure affects the brain. Concretely, changes at this levelwhich occur between seasons, would have a considerable impact on a person. Seasonal depression (SAD), for example, is depression resulting from a lack of natural light. Recently, scientists have studied this phenomenon deeper, upat the level of neurons.
The team used mice to carry out the observations. These concerned, among other things, the suprachiasmatic nucleus neurons (SCN). The neurons in question coordinate with each other in order to adapt to various exposure times in sunlight. Changes occur both at the level of individual neurons and across the entire network.
The study on the subject was published in Science Advances September 2nd. Among the authors is Alessandra Porcu, as well as Davide Dulcis. They are both neuroscientists from University of California San Diego.
Links between exposure to light and mood?
the suprachiasmatic nucleusmentioned earlier, plays an extremely important role in the biological rhythm of the body for 24 hours. How it works also affects the paraventricular nucleus (PVN). The PVN has several roles in behavior regulation. It manages, for example, metabolism, stress, biological growth as well as stress.
Concretely, scientists have already identified that changes in the SNA can influence the operation of the PVN. They were thus able to make the link, at the molecular level, between sunlight and human behavior.
“The most impressive result of this study is that we discovered how to artificially manipulate the activity of specific SCN neurons and successfully induce dopamine expression in the hypothalamic PVN network. »
New treatments for neuronal disorders?
During their work, the scientists opted for the mouse, because its brain has great similarities with that of humans. However, care should be taken in interpreting these results, since the study is still in its infancy. In addition, researchers have yet to determine whether neurons of both species have a strictly similar functioning.
However, a discovery of this mechanism will lead to the development of new treatments. These could be used to treat neuronal disorders with light therapy.