tatCN21 reduces the single GABAA channel conductance in neurons from trained rats only. A, B, Current–variance plot extracted from the peak scaled mIPSCs before and after tatCN21 application. Examples from a pseudo-trained rat cell (A) and a trained rat cell (B) are shown. As evident from the initial slope of the parabola, tatCN21 reduced the single-channel current only in the trained neuron. C, The average GABAA single-channel conductance is significantly reduced after drug application only for neurons from trained rats. Values represent the mean ± SE (*p < 0.05). D, The average number of active GABAA channels per event is not modified by drug application in the three groups. Average values were calculated using 5 cells taken from 5 naive rats, 10 cells taken from 8 trained rats, and 5 cells taken from 4 pseudo-trained rats.