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

Figure 4

LFS-induced DP in epileptic tissue is NMDA receptor-dependent. (a, b) Time course of the experiment showing the relative fEPSP slope (in % baseline). The NMDA receptor blocker D-AP5 was applied as indicated by the bar. Now, the fEPSP slope in post-SE tissue (closed symbols) was significantly larger than in control tissue (open symbols) at timepoint 2 (60 min after TBS) but remained significantly enhanced at timepoint 3 (i.e., DP). Thus, D-AP5 blocked LFS-induced DP in post-SE tissue. Sample traces (panel a) were taken at baseline (timepoint 1), directly before LFS (i.e., LTP, timepoint 2), and at the end of the experiment (i.e., DP, timepoint 3). (c) Bar graph summarizing the relative fEPSP slopes (in % baseline) for three different timepoints (baseline, LTP, and DP). Note that timepoints 2 and 3 are in the presence of the NMDA receptor blocker D-AP5. 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).

(a)

(b)

(c)

(d)