The human brain is able to adapt to stress, but the degree of stress varies from person to person, and some people cannot.The reason for this difference is unknown, but to elucidate and prevent the pathophysiology of mental illness such as depression, it is necessary to know what kind of changes occur in the stressed brain. Is important.

　The research group has previously reported a decrease in sirtuin gene (SIRT1) expression in depressed patients, but the causal relationship between SIRT1 expression / dysfunction and stress-induced depression remains. I'm not sure.In this study, we conducted a test to measure anxiety behavior by stressing BALB / c (BALB) mice and C57BL / 6 (B6) mice with different genetic backgrounds, and what kind of difference can be seen in their brains. I observed.As a result, in BALB mice with increased anxiety / depression-like behavior, the amount of SIRT1 decreased in the part of the brain called the hippocampus.There was no change in the amount of SIR6 in B1 mice that did not show any increase in anxiety behavior.It was also found that activating SIRT1 in the hippocampus of BALB mice with a drug makes them more resistant to stress, and conversely, weakening the action of SIRT1 makes them unable to adapt to even mild stress.

　To confirm whether this SIRT1 is essential for stress response, the hippocampus of BALB mice was overexpressed with wild-type SIRT1 and DN-type SIRT1 that inhibits activity, respectively. As a result, anxiety behavior increased in mice overexpressing DN type. On the other hand, in mice overexpressing the wild form, anxiety behavior disappeared and they became more adaptable to stress.From these results, it can be said that SIRT1 is an important factor in the stress response.

　It is hoped that further research will be carried out in the future to elucidate the entire picture of the stressed brain, elucidate the causes of depression and anxiety disorders, and promote efforts toward the development of new therapeutic agents targeting SIRT1. increase.