Enhancement of synaptic transmission in the IC after tail amputation. (A) The input–output relationship of the fEPSP slope in the superficial layer of the IC. Shown are the percentage changes of the fEPSP slope (normalized to the slope value at 8 μA) in response to series of ascending stimulation intensities. Tail amputation (n = 6 slices/4 mice) caused a leftward shift of the input–output curve compared to the sham control group (n = 6 slices/6 mice). (B) Pooled data of the input–output relationship of the fEPSP slope in the deep layer of the IC. Similarly, tail amputation (n = 6 slices/4 mice) resulted in a leftward shift of the curve compared to the sham control (n = 5 slices/5 mice). The insets in (A) and (B) show the representative fEPSP traces recorded at 18 μA for both sham (left) and tail-amputated (right) groups. Calibration: 100 μV, 10 ms. (C) The input-out curve of the number of activated channels obtained at graded stimulation intensities in the IC slice. Significant difference was detected between the sham control (n = 6 slices/6 mice) and tail-amputated (n = 8 slices/5 mice) group at higher stimulation intensities. Error bars represent SEM.