Excessive mental stress causes stress-induced psychiatric symptoms such as anxiety and depression.What is the cause of individuals who are prone to developing psychiatric symptoms and those who are not?

　The researchers hypothesized that stress memory might be a factor in the onset of psychiatric symptoms. rice field.As a result, it was first found that mice with more "ripple waves" observed in the ventral hippocampus after stress stimulation were more likely to exhibit depression-like symptoms.Ripple waves are characteristic electroencephalograms that are important for fixing memories in the brain.In other words, the occurrence of ventral hippocampal ripple waves that strengthen stress memory may facilitate the development of subsequent stress-induced psychotic symptoms.

　Therefore, in an experiment in which hippocampal ripples in stress-loaded mice were extinguished by instantaneous feedback stimulation, it was found that the onset of depression-like symptoms in mice was suppressed.In addition, since it is known that ripple waves rarely occur during exercise, as an effect in a more natural environment, when stressed mice were exercised on a walking machine, the frequency of ripples decreased significantly. The onset of depression-like symptoms was also suppressed.

　From the above, stress memory enhanced in the hippocampus is important for the onset of psychiatric symptoms, and reducing the frequency of hippocampal ripple waves through exercise (distraction) after stress is effective in suppressing the onset. became clear.

　The results of this study indicate the relationship between memory and the onset mechanism of stress-responsive psychiatric symptoms, which has been largely unexplored so far, and is expected to provide an important opportunity to improve mental health in a modern stressful society. be.

Paper information:[Nature Communications] Hippocampal sharp wave ripples underlie stress susceptibility in male mice