A, typical spontaneous miniature postsynaptic currents (mIPSCs) observed before, during and after the application of 10−6m strychnine in the presence of 3 × 10−7m TTX, 3 × 10−6m CNQX, 10−5m AP5 and 3 × 10−6m bicuculline. Insets indicate the current recordings with an expanded time scale. Ba, typical traces recorded from a neurone at various holding potentials. Bb, the I–V relationship in which each point is the mean of 4 neurones.