IMPAIRMENT OF MOTOR COORDINATION, PURKINJE-CELL SYNAPSE FORMATION, AND CEREBELLAR LONG-TERM DEPRESSION IN GLUR-DELTA-2 MUTANT MICE

Of the six glutamate receptor (GluR) channel subunit families identifi ed by molecular cloning, five have been shown to constitute either the AMPA, kainate, or NMDA receptor channel, whereas the function of the delta subunit family remains unknown. The selective localization of th e delta 2 subunit or the GluR delta subfamily in cerebellar Purkinje C ells prompted us to examine its possible physiological roles by the ge ne targeting technique. Analyses of the GluR delta 2 mutant mice revea l that the delta 2 subunit plays important roles in motor coordination , formation of parallel fiber-Purkinje cell synapses and climbing fibe r-Purkinje cell synapses, and long-term depression of parallel fiber-P urkinje cell synaptic transmission. These! results suggest a close rel ationship between synaptic plasticity and synapse formation in the cer ebellum.