In the present study we found that large amount of superoxide anion was generated in the hippocampus of PTZ-kindled mice, and this newly generated superoxide anion rapidly reacts with nNOS-derived NO and produces plenty of peroxynitrite, which has been implicated in the pathology of various neurological disorders, including epilepsy (Chuang et al., 2009; Gonzalez-Reyes et al., 2016). Here, NOS1 is linked to epilepsy.