A research group led by Professor Takuya Takahashi, Physiology, Yokohama City University School of Medicine, has developed a molecular cell mechanism that increases aggression due to a rearing environment that is socially isolated from mothers and other children, as seen in neglect. It was clarified for the first time in the world.

　Neglect is said to account for nearly 40% of all abuses, and many abandoned children are exposed to a socially isolated environment.Such a rearing environment is considered to be one of the causes of borderline personality disorder, and it has been reported that it causes an increase in aggression in particular.However, the biological mechanism of why such a rearing environment causes increased aggression was unclear.

　The research group used viral in vivo gene transfer and electrophysiological techniques to increase aggression in rats experiencing social isolation during development, and AMPA receptor synaptic translocation in the medial prefrontal region. It was revealed that it is inhibited, that it is mediated by the stress hormone glucocorticoid, and that changes and increased aggression at this synapse are mediated by the cytoskeletal regulator cophyllin.

　The medial prefrontal cortex plays an important role in social behavior.The present study found that stress from social isolation in early childhood causes functional decline in the medial prefrontal cortex by reducing brain function (plasticity) that changes in response to external stimuli.

　This result not only leads to the elucidation of the physiological mechanism in severe social disorders caused by poor rearing environment, but also makes it possible to search for compounds that restore the phenotype by advancing the analysis of "socially isolated animals". It is expected that this will be a clue to the development of new therapeutic agents.