JUN-B EXPRESSION IN PURKINJE-CELLS BY CONJUNCTIVE STIMULATION OF CLIMBING FIBER AND AMPA

CO-APPLICATION of lpha-amino-3-hydro-5-methyl-4-isoxazole-propionate ( AMPA) and 8-bromo cGMP (8-Br-cGMP) which cause long-term desensitizati on also induces c-Fos and Jun-B expression in Purkinje cells of cerebe llar slices [Nakazawa K, Karachot L, Nakabeppu Y et al. NeuroReport 4, 1275-1278 (1993)]. Here, we report an increased local induction of Ju n-B immunoreactivity in Purkinje cells in vivo when electrical stimula tion of the inferior olive nucleus (IOn) was conjunctively applied wit h AMPA on the vermis. The present data further supports the idea that conjunctive heterosynaptic inputs to cerebellar Purkinje cells can tri gger active gene transcription thus possibly contributing to cerebella r long-term plasticity. They also demonstrate that Jun-B may be a usef ul transcriptional marker to study cerebellar coincidence phenomena.