(A) Baseline electrocorticogram (ECoG) recordings in P16 wild-type (+/+) mice show uneventful 35–50 uV and 5–7 Hz oscillations. (B) ECoG of P16 SSADH (−/−) mice reveals 250–300 uV, 5–7 Hz spike-and-wave discharges (SWD) lasting 3–6s duration. This was associated with frozen stare and vibrissal twitching, suggesting absence seizures. (C) ECoG recording in P20 SSADH(−/−) mice show a transition from absence to a generalized 600 uV at 5 Hz followed by 1.5 to 2 Hz SWD associated with tonic-clonic seizures (arrow). LF= left frontal, RF= right frontal, LP= left parietal, RP= right parietal. (Reproduced with permission from: Cortez et al. Pharmacol Biochem Behav 2004;79:547–53.)