PKC, but not CaMKII or PKA, is involved in the rescue of LFS-evoked insular LTD in the deep layer. (A) Vehicle control group exhibited the normal rescue of insular LTD (n = 5 slices/3 mice). (B) Co-application of the PKC inhibitor chelerythrine (Che, 3 μM) together with DHPG (20 μM, 20 min) blocked the LTD rescue (n = 6 slices/6 mice). (C) CaMKII inhibitor KN62 (5 μM) could not affect the LTD recovery (n = 6 slices/5 mice). (D) PKA inhibitor KT5720 (1 μM) had no effect on DHPG-primed insular LTD (n = 7 slices/5 mice). Inset traces in (A-D) show representative fEPSPs at the time points indicated by the numbers in the graph. Calibration: 100 μV, 10 ms. Horizontal bars denote the period of DHPG application or LFS delivery as indicated. (E) Bar histogram summarizing the averaged data within the last 10 min of the LTD recording. ***P < 0.001. NS, no significance. Error bars represent SEM.