Spontaneous activity, membrane, and action potential properties of wild-type and Kir4.1 cKO pyramidal neurons. A, Representative whole-cell currents of WT and Kir4.1 cKO CA1 pyramidal neurons. B, Influence of the stimulation intensity on the action potential frequency in WT and Kir4.1 cKO neurons. Mean ± SEM. C, Representative sEPSC recordings. D, sEPSC frequency and peak amplitude in WT and Kir4.1 cKO CA1 pyramidal neurons. Mean ± SEM; *p < 0.05.