The role of ERKI/II in late phase LTP: 2001 International Society for Neurochemistry

Extracellular regulated kinases (ERKI/II). members of the mitogen-activated protein kinase (MAPK) family. playa role in long-term memory and in long-term potentiation (LTP). We show that ER K 1/11 is required for the induction of both early and late phases of tetanus-induced LTP in area CA1 il in virto. We show further that ERKIIII is necessary for the up-regulation of immediate early genes which occurs in the dentate gyrus in I'iv(}following the induction of LTP by tetanic stimulation, and in primary cortical cultures exposed to BDN F To test the possibility that stimuli such as BDN F which induce persistent synaptic plasticity arc associated with nuclear translocation of ERKI/II0, we expressed EG FP-ERKII in cell lines and in primary cultures. We observed translocation of EGFP-ERKII from cytoplasm to nucleus in primary cortical cultures exposed to BDNF Our results suggest that the induction of late LTP involves translocation of ERKI/II to the nucleus to activate transcription of immediate early genes. The ability to visualize the cellular redistribution of ER KIJ following stimuli that result in long-term synaptic plasticity suggests that EGFP-ERKII may be a useful new molecular marker for visualizing neuronal circuits underlying information storage in the brain in vivo.