Figure 1.

Cd²⁺ reduces spontaneous release of GABA but not glutamate in acute neocortical slices. A, Exemplary current traces showing mEPSCs (red) before (top trace) and during (middle trace) application of 100 μm Cd²⁺. Calibration: 20 pA, 100 ms. The bottom trace shows superimposed average mEPSCs after normalization for amplitude. Calibration: 5 ms. B, Histogram of average mEPSC amplitude in control conditions and in the last 2 min of Cd²⁺ application. Open circles linked with lines represent average mEPSC amplitudes from individual experiments (n = 6). C, Exemplary current traces showing mIPSCs (blue) before (top trace) and during (middle trace) application of 100 μm Cd²⁺. Calibration: 60 pA, 100 ms. The bottom trace shows superimposed average mIPSCs after normalization for amplitude. Calibration: 5 ms. D, Histogram of average mIPSC amplitude in control conditions and in the last 120 s of Cd²⁺ application (n = 6). E, F, Exemplary (open circles) and normalized average (closed circles) diary plots showing the effect of 100 μm Cd²⁺ (bar and dotted lines) on mEPSC (red) and mIPSC (blue) frequency (mean ± SEM) versus time. Average effects measured over the last 5 min of drug application relative to basal frequency (averaged over the 5 min before application) are shown in this figure and diary plots in Figures 4 and 5.