Fig. 2. Behavioral seizure analysis. Effect of i.p. injection of kainate (15 mg/kg) on behavioral scores. The initial 2 hours after the application of KA or saline were evaluated using an adapted version of Morrison's Seizure Rating scale [29]. Only when kainate was injected, normal explorative behavior ceased within ten minutes and higher seizure stages were developed during the observation period. Under histidine with no kainate, or under Zn-histi­dine with no kainite, most the time normal behavior (stage 0) was observed. Only in six out of 50 mice (both genotypes) stage 1 was reached (immobility, exhibiting a rigid posture and staring into space). A. Higher seizure scores evaluated as maximal scores (score 6 and/or 7) are plotted for Ca_v2.3-competent mice (Ca_v2.3+|+). For comparison reasons, maximal scores for the injection of histidine (1 mM) plus ZnCl₂ (nominally 10 µM) without KA-injection was shown, which is close to zero. B. Higher seizure scores evaluated as maximal scores (score 6 and/or 7) are plotted for Ca_v2.3-deficient mice (Ca_v2.3-|-). For comparison reasons, maximal scores for the injection of histidine (1 mM) plus ZnCl₂ (nominally 10 µM) without KA-injection was shown, which is close to zero.