April 16, 2019
Keio University School of Medicine
A research group led by Associate Professor Kenji Tanaka of the Department of Neuropsychiatry, Keio University School of Medicine, has revealed through experiments with mice that a decrease in the activity of the ventral hippocampus is essential for persevering in behavior until a goal is achieved, and that this decrease in activity is caused by an increase in the activity of serotonergic neurons.
Motivated behavior, the act of tackling things with motivation, is underpinned by two factors: (1) setting a goal and taking the first step, and (2) continuing the behavior until the goal is achieved. While the brain mechanism behind the former has been the subject of much research, including by our research group at the Department of Neuropsychiatry, School of Medicine, the mechanism for the latter had remained unelucidated until now.
The research group focused on the ventral hippocampus, which is known to become more active when anxiety increases, and investigated the relationship between the continuation of motivated behavior and ventral hippocampal activity. The results showed that during the continuation of motivated behavior, the activity of the ventral hippocampus is suppressed, and that if the behavior is stopped before the goal is achieved, the suppression of ventral hippocampal activity is released (returns to its original state). Furthermore, it was found that the suppression of ventral hippocampal activity is brought about by the hyperactivity of serotonergic neurons.
While it is understandable from experience that high anxiety makes it difficult to concentrate on motivated behavior and that a sense of security brings about the persistence and tenacity of behavior that leads to success, this research provides the world's first scientific evidence elucidating the underlying neural mechanism.
The results of this study were published in the online edition of *Nature Neuroscience*, a specialized journal in the field of neuroscience, on April 15, 2019 (UK time).
Please see below for the full press release.