Tadafumi Kato is a Senior Team Leader and the Deputy Director of RIKEN Brain Science Institute. He received an M.D. from the University of Tokyo, with residency training at the University of Tokyo Hospital. He received his Ph.D. from Shiga University of Medical Science, where he began his work on magnetic resonance spectroscopy in bipolar disorder and identified impaired energy metabolism in the brain.

In studying the neurobiology of bipolar disorder, Dr. Kato found that mitochondrial DNA deletions were accumulated in the postmortem brains of bipolar patients. Using model mice that have accumulated mitochondrial DNA deletions in the brain, Dr. Kato’s research team has found that the mice show recurrent spontaneous depression-like episodes which responded to lithium, and has identified a region of the brain involved in these episodes. This would be the first animal model of spontaneous recurrent depression-like episodes that would be potentially useful for development of mood stabilizers. The local mitochondrial dysfunction was verified in the postmortem brains of patients with mitochondrial disease with mood symptoms. Dr. Kato’s series of work has established the role of mitochondrial dysfunction in bipolar disorder.

His research group has also been working on genomic analyses of bipolar disorder, publishing one of the first comprehensive analyses of transcribed genes in the postmortem brains of patients with bipolar disorder. Since then, he and his colleagues have applied similar technologies to clinical samples and also animal models to find dysfunctional mechanisms within bipolar disorder and related disorders. The studies have revealed the role of a type of cellular stress in monozygotic twins discordant for bipolar disorder, the role of a genetic element called retrotransposon LINE-1 in schizophrenia, and de novo (newly generated) mutations related to bipolar disorder.