Late-phase long-term potentiation (L-LTP) and long-term memory depend on the transcription of mRNA of CRE-driven genes and synthesis of proteins.However,how synaptic signals propagate to the nucleus is unclear.We report that the CREB coactivator TORC 1 (transducer of regulated CREB activity 1) undergoes neuronal activity-induced translocation from the cytoplasm to the nucleus,a process required for CRE-dependent gene expression and L-LTP.Overexpressing a dominant-negative form of TORC 1 or down-regulating TORC 1 expression prevented activity-dependent transcription of CREB target genes in cultured hippocampal neurons,while overexpressing a wild-type form of TORC 1 facilitated basal and activity-induced transcription of CREB target genes.Furthermore,overexpressing the dominantnegative form of TORC 1 suppressed the maintenance of L-LTP without affecting early-phase long-term potentiation,while overexpressing the wild-type form of TORC 1 facilitated the induction of L-LTP in hippocampal slices.Our results indicate that TORC1 is essential for CRE-driven gene expression and maintenance of long-term synaptic potentiation.