FIGURE 10.
Model of translational control during Arc-dependent LTP consolidation in the dentate gyrus. The diagram depicts ERK and mTORC1 signaling pathways regulating eIF4E and p70S6K-rpS6. After LTP induction in the dentate gyrus, ERK-MNK signaling (but not rapamycin-sensitive mTORC1 signaling) is necessary for eIF4F formation, eIF4E phosphorylation, and Arc synthesis. HFS activates mTORC1 but does not promote dissociation of 4E-BP2 from eIF4E (dashed line). mTORC1 activation is necessary for p70S6K-rpS6 phosphorylation and enhanced synthesis of select translation factors, but blockade of these effects with rapamycin does not affect LTP. The present data, therefore, indicate a dominant role for ERK-MNK signaling in translational initiation and Arc synthesis underlying LTP consolidation in the dentate gyrus. Cross-talk between ERK and mTORC1 in regulation of translation factor synthesis is not depicted. The role of p70S6K-rpS6 signaling is unknown and may not be involved in translation factor synthesis.