A research group led by Professor Noriko Osumi (Tohoku University Graduate School of Medicine) found that arachidonic acid, a type of polyunsaturated fatty acid (PUFA), promotes neurogenesis and improves behaviors in psychiatric disorders in rats as well.  The work was mainly supported by a basic research project (CREST) of Japan Science and Technology Agency (JST).

Patients with psychiatric disorders such as schizophrenia show a symptom of weakening the sensory filtering function.  This sensory filtering function blocks unnecessary noises or information in order to controls excessive and chaotic signs in human brains.  It can be biologically measured by calculating the startle response called prepulse inhibition (PPI).

The research group shows the correlation between the reduction of neurogenesis and PPI deficits in animals with impaired gene Pax6 which plays important role to develop brain, or in animal models with the reduction of neurogenesis by medicat ions.  In addition to this finding, arachidonic acid appears to be a potential benefit of promoting neurogenesis based on the previous research results that proteins bind PUFA are related to neurogenesis.

In this study, wild rats have been fed with arachidonic acid for 4 weeks after birth.  As a result, neurogenesis increased 30% compared with controls.  Moreover, when Pax6 deficient rats have been fed with arachidonic acid, neurogenesis also increased and PPI deficits were alleviated.

These findings suggest that arachidonic acid possibly promotes neurogenesis and improves behaviors in psychiatric disorders.  It is expected that mental disorders cause of PPI deficits may be prevented or treated by taking arachidonic acid.

The research results have been published in “PLoS ONE” (U.S. online science journal) on April 8, 2009.  This collaborative research project has been done by Dr. Takeo Yoshikawa and Dr. Motoko Maekawa, Team Leader and Fellow of Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, repectively, Dr. Kaoru Inokuchi, Senior researcher at Mitsubishi Kagaku Institute of Life Sciences, and Dr. Yoshinobu Kiso, Director at Institute for Health Care Science, Suntory Co. Ltd.

Professor Noriko Osumi
Tohoku University Graduate School of Medicine
Address: 2-1 Seiryo-cho Aoba ward, Miyagi, 980-8575, Japan
Tel：+81-22-717-8201 Fax：+81-22-717-8205
E-mail：osumi@mail.tains.tohoku.ac.jp