Toward and beyond synaptic plasticity

Through the latter half of the 20th century, one of the major research themes in neuroscience has been synaptic transmission and its plasticity. Synaptic plasticity has been conceived as the neural basis of memory and learning, and three concrete forms of it have been described: sensitization, long-term potentiation (LTP), and depression (LTD), (13, 14 30). The complex signal transduction mechanisms underlying these forms of synaptic plasticity have since been revealed, and our knowledge base has expanded to the gene regulatory processes that operate behind these mechanisms. The roles played by synaptic plasticity in brain's memory and learning functions have also been studied extensively. In the cerebellum, the mechanism of LTD has been investigated in Purkinje cells in slices or tissue culture, and the roles of LTD in various forms of movement adaptation have been analyzed. This article reviews the developments in the study of synaptic plasticity focusing on the cerebellum, and discusses future perspectives of neuroscience beyond this.