After a stress response, changes occur in the behaviour of the individual as well as in the immune and haematopoietic systems, sometimes leading to the development of disorders. We have found that the responsiveness and character of cells involved in biological control are altered after a stress response. Focusing mainly on monocytic cells, we are trying to elucidate the pathways through which changes at the cellular level are involved in the initiation and maintenance of disorders after stress.

Even cells of the immune system express receptors for hormones and neurotransmitters and are subject to their influence. We are investigating whether and how endocrine and nervous systems influence on the differentiation, acquisition of function and subsequent changes in immune cells.

Impaired social behaviour may be observed in the prodromal phase of depression and schizophrenia, and is also a risk factor for prognosis. With the aim of reducing this risk and avoiding the diseases, we generated animal models with impaired social interaction and withdrawal behaviours and classified them by behavioural phenotype. By analyzing the expression of brain genes, we are trying to elucidate the pathways in the brain that lead to the impairment of various social behaviours, and furthermore, to suppress the impairment. On the other hand, we are working to establish translational biomarkers for psychiatric disorders and adjustment disorders by analyzing and matching human specimens with clinical information (Seeds have been registered in the Department of Future Medical Development, Osaka University Hospital, and some of the results are being commercialized and disseminated).

The psycho-neurological, immunological and endocrine systems mutually regulate each other to establish a Host-defence mechanism. We have found that gene expression patterns, innate immune cell functions, and energy metabolism are altered in peripheral organs and tissues in response to stress exposure and behavioral impairment phenotypes. In order to explore the possibility of organ- or tissue-psycho-social biological control, we are investigating the pathways linking peripheral tissues to the brain and to behaviour.