The maintenance of DG LTP in vivo is normal in Arc KO animals. A, There was no significant difference in basal synaptic transmission between the Arc^GFP/GFP KO (red circles) and WT (black circles) littermates in the dentate gyrus in vivo. B, The magnitude of LTP over the first 5 min poststimulation was significantly enhanced in Arc^GFP/GFP KO animals compared with WT littermates, but was not significantly different over the last 5 min of recording when LTP was induced using a theta-burst stimulation protocol (4 trains at 10 s intertrain intervals; each train consisted of 10 bursts at 5 Hz, with each burst containing 4 stimuli at 100 Hz). Data are represented as mean ± SEM. Scale bars: 5 mV (horizontal) and 5 ms (vertical).