We investigated evoked EPSPs and spontaneous IPSPs in cerebellar slices from dystrophin-deficient mdx mice. In the presence of the GABA(A) antagonist bicuculline the increase in EPSP amplitude was less in mdx Purkinje cells compared to control, and the amplitude of miniature IPSCs in mdx cells was also significantly less than in controls. This reduced inhibitory input is most likely due to the reported reduction in the size of GABA(A) channel clusters.