The effects of vigabatrin on type II spike wave discharges in rats

The antiepileptic drug vigabatrin increases GABA concentrations by inhibiting GABA transaminase. The effects of vigabatrin on type 11 spike wave discharges (SWDs) in the electroencephalogram of ACI rats were studied in order to learn more about the effects of altering GABA concentration on SWDs. The incidence of type II SWDs increased after vigabatrin (60/h) as compared to saline treatment (3.7/h). This effect appeared with a halftime of 100 min. The duration of type II SWDs increased after vigabatrin (1.52 s) as compared to saline treatment (1.04 s), but the peak-frequency of the type 11 SWDs decreased after vigabatrin (5.6 Hz) as compared to saline treatment (7.5 Hz). Thus, vigabatrin alters the type II SWD morphology. These results are in agreement with predictions of Destexhe's theoretical model, modulating both GABA(A) and GABA(B) conductances. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.