Figure 4.

HFS induces LTP of NMDAR EPSCs. (A) Twenty-four stimuli at 25 Hz (arrow) was sufficient to induce NMDAR LTP. Example traces show EPSCs during baseline (black) and after HFS (red). PPR was unchanged by NMDAR LTP induction. DCG-IV (1 μm) was applied at the end of each experiment to confirm mossy fiber input. B, The NSP was sufficient to induce NMDAR LTP but did not change PPR. C, Twenty-four stimuli at 25 Hz was insufficient to induce KAR LTD or change PPR. D, Twenty-four stimuli at 25 Hz was insufficient to induce KAR LTD with NMDAR unblocked. D-AP5 (50 μm) was washed out for 15 min before presentation of 24 stimuli at 25 Hz and then immediately reapplied. Example traces show EPSCs during baseline (black), after D-AP5 washout (red) and after HFS and reapplication of D-AP5 (green). E, Ten stimuli at 25 Hz was insufficient to induce NMDAR LTP or change PPR.