Two teams of researchers have identified groups of neurons that, when stimulated, put the mice in a state of artificial hibernation.
Two studies have revealed mechanisms that can be used to induce mice to go into artificial hibernation, a state in which metabolism slows down and body temperature drops to save energy, something that happens naturally in some animals during the winter.
Despite not hibernating, mice can go into a torpor state, triggered by a lack of food and low temperatures, during relatively short periods. The researchers have now been able to identify the genetics and physiology of the mice that lead to that state and the neurons that control it.
Scientists in Boston, in the United States, were able to monitor activity in 190 regions of the animals’ brains, comparing data from those who were in induced torpor, from those that remained active.
Then they injected chemicals into these regions to activate neurons and concluded that by activating those in the anterior hypothalamus they can induce a state equivalent to torpor.
The second team, based in Japan, followed a protein (related to eating and anxiety) to the cells that produce it in the brain and studied it in detail. After manipulating these cells, the scientists managed to get them to produce the same chemical injected by the Boston team.
When the correct cells were injected, the mice also fell into a state equivalent to torpor. The body temperature (usually above 40 degrees) dropped below 30 degrees for 48 hours, cardiac activity decreased and oxygen consumption was reduced.
Scientists will continue to study these neurons and try to identify more benefits from this artificial state of hibernation. The scientific articles (which can be consulted here and here) were both published in Nature.