Pharmacological rescue of LFS-evoked insular LTD in the tail-amputated mice by group I mGluR activation. (A and B) An overview of 64-channel multi-electrode array recordings in the tail-amputated IC slice (A: before LFS; B: 60 min after LFS). DHPG (20 μM) was applied for 20 min followed by washout for 30 min. Then LFS was given. Bath application of low dose of DHPG only elicited acute depression. However, subsequent LFS induced clear LTD after priming with DHPG. Red dots denote the stimulation sites in the deep layer. Calibration: 100 μV, 10 ms. (C and D) One representative example slice showing the rescue of LFS-induced LTD by DHPG priming in both superficial layer (C) and deep layer (D) of the IC. Inset traces show representative fEPSPs at the time points indicated by the numbers in the graph. Calibration: 100 μV, 10 ms. (E and F) Summarized data for the superficial layer (n = 6 slices/5 mice) and deep layer (n = 5 slices/5 mice). Horizontal bars denote the period of DHPG application or LFS delivery as indicated. Error bars represent SEM.