Bipolar Disorder is a mental illness with extreme fluctuations of mood from the elevated mania to deep depression. Current medications produce severe side effects for a majority of people, and discovery of new and more effective medication is desired.

Diacylglycerol kinase β (DGKβ) is an enzyme which phosphorylates diacylglycerol to produce phosphatidic acid.  It has been reported that the COOH-terminal of DGKβ protein is lacking in bipolar disorder patients. Prof. Hara and his team developed DGKβ knock-out mice for a bipolar model, using a technology originally developed at Osaka University.

The results of several behavior tests of the DGKβ knock-out mice demonstrated similarities with manic patients, including hyperactivity, impaired memory, and lithium response. This mouse model can be a very good tool to facilitate understanding the disease and discovery of new medications.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the EGF family, serves as a neurotrophic molecule, and plays a significant role in the brain.  Prof. Hara and his team developed HB-EGF knock-out mice for a model of psychiatric disorders, such as schizophrenia.

This mouse model showed behavioral abnormalities and altered monoamine levels similar to those described in schizophrenic patients, as well as decreased spine density. These results suggest that this mouse model may be useful for research into pathogenesis and new medications for psychiatric disorders, such as schizophrenia.