Sulfolane effects on audiogenic, pentylenetetrazol and afterdischarge seizure activity.

Sulfolane dosages that alter seizure susceptibility were determined using audiogenic (AG), pentylenetetrazol (PTZ) and hippocampal afterdischarge (AD) seizure models. The presence of AG seizures and potentiation of PTZ seizures were investigated in rats injected IP with 0, 200, 400 or 800 mg/kg; AD activity was assessed only at the highest and lowest dosages. The dose-dependent hypothermia associated with sulfolane treatment was controlled in Experiment I and a replication study (Experiment II) by testing under isothermic conditions. The effect of body temperature was measured directly in Experiment III by comparing AG seizure incidence and characteristics exhibited by hypothermic and normothermic animals. Audiogenic seizures were elicited in nearly half of the 800 mg/kg animals in both Experiments I and II. Sulfolane-induced hypothermia, maximal at 3 hours, partially protected against AG seizure characteristics. Potentiation of PTZ seizure severity (800 mg/kg) and duration (800 and 400 mg/kg) also were observed. None of the hippocampal AD parameters was affected significantly by sulfolane treatment. The similarity of the convulsants sulfolane and PTZ is discussed.