In our study, following a saline injection and 30 min recording of baseline ECoG, rats were treated i.p. with GHB at 100, 200, 400, and 800 mg/kg and recording continued for the next 60 min. The real-time ECoG recording indicated a dose response in bilateral spike-and-wave discharges consistent with electrographic seizures. These 5-7 sec spikes, initially observed within 7-10 min following 200 mg/kg GHB, were accompanied by a desynchronized ECoG, remaining progressively longer and lasting throughout the 60-min recording period in 400 and 800 mg/kg GHB treated rats. The alterations in ECoG activity were associated with behavioral sedation (“freezing”) characterized by immobility and staring. The FFT analyses of power spectra relative to baseline indicated a significant energy increase over all, except beta2, frequency bands following 400 and 800 mg/kg GHB (Fig. (2)). The significant power increases after 400 mg/kg GHB were observed within approximately 30 min compared to 10-15 min after 800 mg/kg. The EEG alterations detected in rats following exposure to GHB resemble absence seizures observed in human petit mal epilepsy.
