PTZ-induced seizures in male and female WT and fmr-1 KO mice in a pure C57BL/6 background. C57BL/6 mice (8–10 weeks old) were injected intraperitoneally with 50 mg PTZ per kg body weight and seizure activity was monitored for 60 min. Average seizure scores were 2.2±0.33 (WT females, n=10), 3.13±0.19 (WT males, n=15), 2.67±0.37 (fmr-1 KO females, n=9) and 2.9±0.22 (fmr-1 KO males, n=20). The 0.93 difference in seizure grade between the WT male and female mice was statistically significant (p=0.015).