Shigetada Nakanishi

Intercellular communication mediated by neurotransmitters and their receptors in the neural network is a fundamental process responsible for brain function. My laboratory has studied molecular mechanisms and function of excitatory glutamate-synaptic transmission in the central nervous system. We elucidated the molecular nature of N-methyl-D-aspartate and metabotropic types of glutamate receptors by molecular cloning. On the basis of our finding of a molecular diversity of glutamate receptors, we have extended our study to glutamate receptor-mediated sensory processing mechanisms in the visual and olfactory systems. We have also been investigating synaptic plasticity responsible for olfactory and hippocampal memory formation and cerebellar motor coordination. More recently, we have been addressing how synaptic transmission is integrated and modulated in the neural circuit. In combination with cell-ablating techniques with transgenic mice we succeeded in eliminating specific neuronal cells within a particular neural circuit and have been investigating physiological and behavioral roles of synaptic integration in the neural network. In doing this we have focused on the neural circuits in the retina, cerebellum, and basal ganglia and have pursued synaptic integration in these networks, using several approaches, including molecular biology, electrophysiology, and behavioral analysis.