Figure 2. Seizure threshold and spontaneous seizures.

A. Pentylenetetrazole (PTZ)-induced seizures. GS knockout mice (KO, n = 9) demonstrate increased susceptibility to provoked seizures, as they have a shorter time to clonic twitch compared to controls (WT, n = 6, p < 0.05). There was a similar trend in time to convulsion, though this effect was not significant (p = 0.20). B. Representative examples of intracranial EEG recordings during a Racine stage 3 seizure in a GS-knockout mouse (KO). The two upper traces are from a KO mouse and control virus injected “wild type” (WT) mouse. The highlighted area is shown in the expanded traces below. Note the presence of rhythmic seizure activity in the KO mouse and normal EEG activity in the WT mouse. The Racine stage was determined from the concurrent video recording. C. Daily number of electrographic seizures encountered in control (n = 4) and Cre-injected (n = 7) mice over a continuous 4- to 12-day-period starting 4–6 weeks after infusion of AAV8-GFAP-GFP (control) or AAV8-GFAP-GFP-Cre (Cre) into the dentate gyrus of both hippocampi. The days with seizures are highlighted in yellow and days without EEG recording are highlighted in dark grey.