Structural Physiology

Our research aims to understand the pathogenesis and symptomatology of psychiatric disorders, including schizophrenia and depression. To this end, we focus on the fundamental synaptic physiology of monoamine actions, the targets of psychiatric drugs, particularly how monoamines control behavioral learning through plasticity modification. To address this question, we are conducting synaptic research using the two-photon excitation microscopy method established by former Professor Haruo Kasai, who retired in 2022, while integrating various techniques, including molecular biology, electrophysiology, animal behavior experiments, and MRI. Additionally, in collaboration with the Department of Psychiatry, we have cultivated a foundation for translational research, where findings from human studies are applied to animal models. Notably, we have elucidated the mechanism of plasticity modification driven by transient changes in dopamine concentration, which has informed our research into schizophrenia models. Furthermore, we are investigating the mechanisms of plasticity in the frontal cortex, which led to the unexpected discovery of the significant role of microglia in these processes.

1. Iino, Y., Sawada, T., Yamaguchi, Tajiri, M., K., Ishii, S., Kasai, H.^* & Yagishita, S.^* (2020) Dopamine D2 receptors in discrimination learning and spine enlargement. Nature 579: 555-560.
2. Yagishita, S., Hayashi-Takagi, A., Ellis-Davies, G.C.R., Urakubo, H., Ishii, S. & Kasai, H. (2014). A critical time window for dopamine action on the structural plasticity of dendritic spines. Science, 345:1616-1620.