PAIRING-SPECIFIC LONG-TERM DEPRESSION PREVENTED BY BLOCKADE OF PKC ORINTRACELLULAR CA2+

LONG-TERM depression was established in cerebellar Purkinje cells usin g 20 pairings of a brief, high frequency train of parallel fiber stimu lation with a subsequent 100 ms depolarizing current injection. Effect s were assessed on the peak amplitude of Purkinje cell excitatory post synaptic potentials (EPSPs) elicited by single parallel fiber test pu lses. Intradendritically recorded Purkinje cell EPSPs exhibited long-t erm (>20 min) reduction in peak amplitude following paired stimulation but not if pretreated with the protein kinase C inhibitor calphostin C or iontophoretically injected with the calcium chelator EGTA. The si milarity of the stimulation protocol and behavioral conditioning parad igms suggests pairing-specific long-term synaptic depression is a valu able model for understanding the cellular mechanisms underlying cerebe llar cortical contributions to learning. Neuro Report 9: 2237-2241 (C) 1998 Rapid Science Ltd.