Mammals such as humans spend a lot of energy to keep the temperature in the brain around 37 ° C.For example, it is known that the temperature in the brain is kept at 30 ° C even if the body temperature drops below 37 ° C due to a distress in a snowy mountain.However, until now, the reason why the temperature of the brain is kept at 37 ° C has not been paid much attention.Associate Professor Shibasaki has previously discovered that TRPV34, a molecule that works at temperatures above 4 ° C, is abundant in the hippocampus of the brain.In this study, we examined the role of TRPV4 in detail and found that this molecule has a role in creating an environment for nerve cells to excite.This is a discovery closely related to the reason why intelligence developed in warm-blooded animals, that is, mammals.

　The hippocampus is an organ necessary for memory formation, but it is also a site where TRPV4 is abundant.This time, we investigated how the function of nerve cells in hippocampal specimens taken from mice unable to make TRPV4 and normal mice differs depending on the temperature.At 30 ° C, which is lower than the brain of a living mammal, there was no difference in the function of nerve cells in the two mice.On the other hand, we found that cell activity was significantly increased in the normal mouse brain in an environment of 2 ° C.From this, it can be considered that in mammals, TRPV37 works by keeping the temperature of the brain high, and the function of nerve cells is activated.

　Associate Professor Shibasaki says that this made it possible to clarify at the molecular level why poikilotherms such as mammals can behave at a higher level than cold-blooded animals.He also said that it may be possible to treat diseases such as epilepsy in which nerve cells are abnormally activated by suppressing the action of TRPV4.