Research Article

Status Epilepticus Enhances Depotentiation after Fully Established LTP in an NMDAR-Dependent but GluN2B-Independent Manner

Figure 1

LFS-induced depotentiation (DP) in post-SE tissue. (a) Sample traces taken at baseline (timepoint 1 in panel (b)), directly before low-frequency stimulation (i.e., fully established LTP, timepoint 2 in panel (b)), and at the end of the experiment (i.e., depotentiation, DP, timepoint 3 in panel (b)). (b) Time course of the experiment showing the relative fEPSP slope (in % baseline). Following 10 min baseline, theta-burst stimulation (indicated by arrow) was applied to induced LTP which was allowed to develop for 60 min. Then, LFS was applied in order to depotentiate synapses again. The effect of LFS-induced DP was assessed after a follow-up of another 60 min (i.e., at 135 min after LTP induction). While there was a significant difference in LTP between control (open symbols) and post-SE tissue (closed symbols), LFS caused DP only in post-SE tissue, but not in controls. (c) Bar graph summarizing the relative fEPSP slopes (in % baseline) for three different timepoints (baseline, LTP, and DP). Diamonds indicate significant differences against baseline. Asterisks indicate significant differences as indicated by the brackets. (d) Paired-pulse ratio (PPR) of synaptic transmission following double-pulse stimulation (interstimulus interval 40 ms) for control (open bars) and post-SE tissue (closed bars) at three timepoints (baseline, LTP, and DP).