Rapidly turned over protein maintains metabotropic synaptic transmission in Purkinje cells

It has generally been thought that protein synthesis is required for relatively slow cellular processes such as synaptogenesis and synaptic plasticity. In this study on rat cerebellar slices, we found that metabotropic glutamate receptor-mediated synaptic transmission to cerebellar Purkinje cells was quickly and persistently depressed by brief (5 min) applications of translational inhibitors, which were confirmed to induce quick and persistent depression of protein synthesis in cerebellar tissues. Brief applications of transcriptional inhibitors also depressed metabotropic synaptic transmission, but progressively over 1 h, presumably due to depletion of mRNAs in the dendrites. Results of this study indicate the presence of a unique protein(s) that is dynamically involved in metabotropic synaptic transmission.