TPH2 and Seizure: Seizure severities, as assessed by the E/F ratios, were comparable between WT (11.03 ± 1.20; n = 25, 12M, 13F) and TPH2-ChR2-YFP mice (8.65 ± 0.811; n = 24, 10M, 14F; Mann–Whitney U test, P = 0.1089; Fig. 2A) and between mice that survived (WT: 9.02 ± 1.20; n = 10, 4M, 6F; TPH2-ChR2-YFP: 8.49 ± 0.98; n = 14, 5M, 9F) versus died (WT: 12.18 ± 1.68; n = 15, 10M, 5F; TPH2-ChR2-YFP: 8.88 ± 1.45; n = 10, 5M, 5F; one-way ANOVA, P = 0.1822, F(3, 46) = 1.690; Fig. 2B).