Tonic and/or clonic convulsions were noted approximately 81 min following the start of PTZ infusion and lasted an average of 120 (83) s, corresponding to a PTZ dose of 56.1 (12.7) mg/kg. The Fig. 1A illustrates EEG ictal activity measured in the cynomolgus monkey at the onset of seizure activity including EEG sharp waves and spike trains. Fig. 1B demonstrates EEG activity throughout the ictal period including post-ictal power attenuation. Several clinical signs, including hypersalivation, decreased activity and ataxia were observed up to 52 min post-ictus. Libraries Pre-ictal spectral changes compared

to baseline data reveal an increase in the higher frequency power bands (i.e. theta to beta) just prior to and during the PTZ induced ictal period ( Fig. 2) while the low Y-27632 in vivo frequency delta band is not see more modified. As noted in Fig. 3, spectral analysis showed changes across a large range of frequencies (0.5–127 Hz) following caffeine administration (10 mg/kg, IM) when compared to time-matched data obtained following administration of saline (negative control). Decreases in low range frequencies (0.5–13 Hz)

and increases in higher frequencies (> 14–127 Hz) were observed with effects dissipating progressively over 12 h following dosing. The Fig. 4 illustrates EEG during ictal activity in a Beagle dog following PTZ IV infusion. Table 2 presents the averaged PTZ doses at onset of premonitory signs including uncoordination/ataxia, excessive vocalization and emesis noted as early as 18 min prior to PTZ-induced seizure. Additional clinical signs, such as hypersalivation, head shaking, excessive panting and tremors were observed between approximately nearly 2 and 10 min prior to convulsions. Clonic convulsions were observed at a PTZ dose of 36.1 (3.8) mg/kg, while tonic convulsions, noted at a PTZ dose of 36.8 (5.4) mg/kg. EEG seizure activity lasted an average of 1 min 23 s as diazepam (1.0 mg/kg) was administered immediately following the onset of convulsions. A second dose of diazepam was administered

to 75% of the animals, 95 (18) s following the first dose, due to signs of EEG instability or recurrence of PTZ-induced seizures. Several clinical signs, including hypersalivation, decreased activity, ataxia, and hypersensitivity were observed for up for to 25 min post-ictus. Spectral analysis revealed important changes in a large range of frequencies (i.e. 0.5–50 Hz). More specifically, when compared to values prior to PTZ infusion, considerable increases in all power bands were observed just prior to seizure onset ( Fig. 5). During the post-ictal period, an attenuation of high frequency power bands (sigma [12–16 Hz], beta [16–24 Hz] and gamma [24–50 Hz]) was observed, with intermittent increases in low frequency power bands (delta [0.5–4 Hz], and theta [4–8 Hz]). This observation is termed “postictal depression”.