Objective: To explore the meaning of activation of NF-κBp65 in rats hippocampal formation and the protective effects and mechanisms of calmodulin inhibitor W-7 on PTZ-induced rats. Methods:Fifty-eight healthy adult Sprague-Dawley rats were randomly divided into 5 groups: control group(i.p.NS), PTZ group(i.p.PTZ 65 mg/kg) and W-7 preteated groups (i.p.W-7 25 μmol/kg, 50 μmol/kg, 100 μmol/kg, followed by i.p.PTZ65mg/kg after 10min of W-7 treatment). Behaviors of rats were observed according to the criteria of Racine. The expression of NF-κBp65 in the hippoacampus of rats as examined by means of immunohistochemistry and Western blotting analysis. Results:Immunohistochemical staining and Western blotting analysis showed that NF-κBp65 was expressed in the hippocampus of all groups. Compared with control group, the expression of NF-κB p65 was increased in PTZ group(P < 0.01), while it was decreased in W-7 groups(P < 0.05,P<0.01). Conclusion:The expression of NF-κB p65 is increased in the hippocampus of PTZ-induced rats. W-7 has protective effects on PTZ-induced rats by depressing expression of NF-κB p65.