Objective Previous reports have shown that N-methyl-D-aspartate (NMDA) receptors are extensively involved in epilepsy genesis and recurrence.Recent studies have shown that synaptic and extrasynaptic NMDA receptors play different, or even opposing, roles in various signaling pathways, including synaptic plasticity and neuronal death.However, few studies have focused on the role of extrasynaptie NMDA receptors in epileptogenesis.Therefore, in the present study we analyzed extrasynaptic NMDA receptor-mediated currents during the early stage of epileptogenesis.Methods Adult C57BL/6 mice models of pilocarpine-indueed epilepsy were established, and hippocampal slices were prepared at 24 h after the onset of status epilepticus.Changes in synaptic and extrasynaptic NMDA receptor-mediated excitatory post-synaptic currents (NMDA-EPSCs) were recorded in CA1 pyramidal neurons by whole-cell patch clamp technique.Results (1) There were no significant differences in synaptic NMDA-EPSCs between pilocarpine (n =10) and control (n =7) groups in terms of rise time and decay time.(2) Similarly, the peak amplitudes and rise time of extrasynaptic NMDA-EPSCs were not statistically different between the 2 groups.(3) However, extrasynaptic NMDA-EPSCs decayed significantly faster in the pilocarpine-treated mice.Conclusion During the early stage of epileptogenesis, the channel properties of extrasynaptic but not synaptic NMDA receptors were altered.Our data suggest that extrasynaptic NMDA receptors play an important role in epileptogenesis.