[Study on mental diseases: neural stem cells].

The neurosciences to understand the pathophysiology of psychiatric disorders such as depression and schizophrenia were started from the analysis of neurotransmitter function change, and proceed to the cellular signaling change in the brains. In the next step, it developed to the studies of neuroplasticity change through expressions various cytokines and transcriptional factor regulations. Recently, the existence of neural stem cells and lineage of stem cells to neurons are identified in the adult mammalian brains. In addition, since the brain structural changes in depression and schizophrenia have well defined by the development of neuroimaging analysis, many researchers have been suggested the relationship between the pathophysiology of these disorders and the dysfunction of neurogenesis which strongly affects the maintenance and repair of brain neuronal network. In this report, we describe the new strategy and approach to the investigation of the treatment of psychiatric illness, and introduce our present study of the way to refine the neural network through promoted actions on stem cell functions such as differentiation to neurons.