KENBIKYO Vol.51▶No.3 2016
â– Review

Role of Glutamate Receptor GluD2 in Development, Maintenance, and Regeneration of Cerebellar Synaptic Circuits

Masahiko Watanabe

Abstract: Mono-innervation by single climbing fibers and segregated dendritic innervation by climbing fibers and parallel fibers are the two distinguishing features of synaptic circuits in cerebellar Purkinje cells. In the process, GluD2 or GluRd2, which is selective to parallel fiber-Purkinje cell synapses, plays key roles in development, maintenance, and regeneration of Purkinje cell circuits through its involvement in the strengthening of synaptic connectivity. This selective strengthening leads to activation of metabotropic glutamate receptor mGluR1 at parallel fiber synapses, which then propels eliminations of surplus climbing fiber synapses from the soma and of ectopic parallel fiber synapses from the proximal dendrite. Through this interplay by GluD2 and mGluR1, two distinguishing features of Purkinje cell circuits develop and maturate.

Key words: Purkinje cell, parallel fiber, climbing fiber, GluD2, mGluR1