Audiogenic seizures and sudden death in D/+ mice. (A) In response to high-intensity acoustic stimulation, D/+ mice exhibit wild-running (purple), a tonic phase characterized by hindlimb extension (teal), a clonic stage (orange) characterized by rapid kicking of the hindlimbs, and recovery (green) as the animal rights itself and resumes normal movement throughout the cage, or sudden death (magenta). Audiogenic seizure behavioral progression in each mouse at developmental time points P15 (B), P20-21 (C), P32 (D), and P49-P69 (E). (B) Only 2 of 8 D/+ mice at P15 exhibited audiogenic seizures. (C) All 13 D/+ mice at P20-21 experienced audiogenic seizures, and 11 of 13 died directly following the tonic phase. The 2 that recovered did so after a relatively extended clonic phase. (D) At P32, all 8 D/+ mice had audiogenic seizures and recovered. (E) In adult D/+ mice (P49-P69), all mice experienced seizures followed by recovery. Duration of seizure phases, latency to seizure onset (F), wild-running (G), tonic phase (H), and clonic phase (I) for D/+ mice ages P20-21 (n = 13), P32 (n = 8), and P49-P69 (14). **, ***, ****, and NS indicate P < 0.01, 0.001, 0.0001, >0.2, respectively, for post hoc comparison between age groups.