NPC treatment rebalances the ipsilesional inhibitory and excitatory tone and promotes contralesional postsynaptic excitatory currents. Properties of excitatory (E) and inhibitory (I) spontaneous postsynaptic currents (s-PSC) recorded by patch clamp on acute tissue slices from ipsilesional peri-ischemic medium spiny striatal neurons (left panels) and contralesional MSNs (right panels) at 10 dpt. In the ipsilesional hemisphere: A, Spontaneous IPSC frequency and amplitude are decreased after ischemia. NPC transplantation induces an increase of sIPSCs in the ischemic striatum. B, Ipsilesional sEPSC frequency is increased upon ischemia and reduced by NPC treatment. The NMDA antagonist MK-801 reduces sEPSC frequency after MCAO but not in control group. NPC transplantation has no effect on overactive NMDA receptors. C, D, NPC transplantation has no effect on sEPSC kinetic properties. In the contralesional hemisphere: E, NPC transplantation has no effect on sIPSCs compared with sham-treated mice. Nevertheless, NPC transplantation reduces presynaptic sEPSCs (F) and potentiates NMDA-dependent postsynaptic sEPSCs (G, H). I, J, The electrophysiological traces are examples of sEPSCs (downward deflections) recorded from striatal neurons of a control, a sham-, and a NPC-treated animal in the ipsilesional (I) and contralesional (J) hemisphere. The effect of MK-801 on NPC-treated neurons is shown. Gray bars represent healthy controls. White bars represent sham-treated mice. Black bars represent NPC-treated mice. n = 3 or 4 mice/group, 4 or 5 neurons /hemisphere. Data are mean ± SEM. *p ≤ 0.05 versus healthy controls (one-way ANOVA, Tukey's post hoc test). ^#p ≤ 0.05 versus sham-treated mice (one-way ANOVA, Tukey's post hoc test).