Two groups of researchers have independently discovered a 鈥渂rain switch鈥� that makes starving mice enter a hibernation-like state to save energy. They hope it may be possible to induce similar states in people.
鈥淪uspended animation could transform medicine and open the door to fantastic possibilities such as space travel and life extension,鈥� says Sinisa Hrvatin at Harvard Medical School.
Many birds and mammals, from hummingbirds to lemurs, lower their body temperature and enter a state of suspended animation as a way to survive when times are tough. Some hibernate through winters, others enter a state called torpor for hours or days to save energy.
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Mice normally enter torpor only when they run out of food, but Hrvatin鈥檚 team genetically engineered some of these animals so that the researchers could control the activity of certain neurons by injecting a chemical. The team showed that stimulating specific clusters of neurons in the hypothalamus can induce a torpor-like state in the mice, even in those that are well fed, and that inhibiting these cells prevents mice entering torpor.
In a separate study, Takeshi Sakurai at the University of Tsukuba in Japan identified the same brain switch using a different approach. Sakurai and his听team looked for neurons in mice that produce a short protein called QRFP, which previous studies had suggested was linked to torpor. They found that stimulating these neurons induced that state. They also found that stimulating the equivalent neurons in rats had the same effect, even though rats don鈥檛 enter torpor normally.
Being able to induce a similar state in people could have many uses in medicine, helping to treat everything from cancer to strokes and injuries, but it isn鈥檛 clear whether this brain switch also exists in humans. 鈥淲e don鈥檛 know if humans have the same cells, and we don鈥檛 know if stimulating them would have the same effect,鈥� Hrvatin says.
Journal references:听Nature,听;
