LTP mechanisms in the dentate gyrus in vivo

This book illustrates some of the various molecular §mechanisms underlying synaptic plasticity in a §subfield of the rat hippocampus called dentate §gyrus (DG). Long-term potentiation (LTP) is a well-§known model for studying strengthening of synaptic §plasticity. In this study, LTP was induced in the §DG by intrahippocampal infusion of brain-derived §neurotrophic factor (BDNF-LTP). Alternatively, LTP §was induced at medial perforant path-granule cell §synapses by high frequency stimulation (HFS-LTP).§The aim of the study was investigation of §transcriptional and translational changes of §activity-regulated cytoskeleton-associated protein §(Arc/Arg3.1) as well as changes in activation of the §translation factors eIF4E (eukaryotic initiation §factor 4E) and eEF2 (eukaryotic elongation factor-2) §during LTP.§We have demonstrated rapid activation of both §translation factors and upregulation of Arc protein §during BDNF-LTP. Additionally, an approach based on §intrahippocampal infusion of Arc antisense §oligodeoxynucleotides showed the importance of §sustained Arc translation for the maintenance of §both BDNF-LTP and HFS-LTP during a restricted time §window.