Two decades ago, a group of researchers from the Beth Israel Deaconess Medical Center, located in Boston, which is a teaching hospital at Harvard Medical School, discovered a cluster of nerve cells in the brain that, according to scientists, could be a kind of “switches” taking the brain to sleep. It was only recently that this hypothesis was confirmed.
In a new study published in the journal Nature Communications, a group of scientists proved that it is the cells located in the hypothalamus in its ventrolateral preoptic nucleus (VLPO) that are actually necessary for normal sleep.
“Our work is only the first test of what happens when your VLPO neurons are activated. The results confirm our initial hypothesis that hypothalamic cells are necessary for normal sleep. ”Said the study’s lead author, Clifford Saper.
During the course of the study, a team of experts tested lab mice that had VLPO cells activated. using different methods. In the first case, the zone was activated using a laser beam, as if “illuminating” them (this process is called optogenetics). In another experiment, the team used a special chemical to selectively activate the VLPO neurons. In either case, the activation of VLPO cells led to sleep.
“We found that when VLPO cells are stimulated one to four times per second, they trigger every time and animals get sleep. However, if you stimulate them faster, they eventually lose this function and stop working. Ultimately, experimental animals develop insomnia. This may be the key to a deeper understanding of this process and the development of new therapies. ”
In addition, Dr. Saper’s team also found that the activation of VLPO cells also causes a decrease in body temperature. It has long been known that in a dream the body temperature drops. But now it has become clear what specific brain area is responsible for this.