The Gamma-Butyrolactone Model of Absence Epilepsy: Acute and Chronic Effects in Wistar Rats

Objectives: We studied the electroencephalographic (EEG) and behavioral changes of the chemical model of generalized absence epilepsy induced by acute and chronic administration of gamma-butrolactone (GBL), a prodrug of gamma-hydroxybutyric acid.Methods: Adult male Wistar rats under anesthesia were implanted with bilateral cortical recording electrodes. The rats were administered 30 intraperitoneal injections of GBL twice daily from Monday to Friday and EEG was recorded 20 min before and 40 min after GBL injections. In order to monitor spontaneous spike-and-wave discharges (SWDs), the baseline EEGs on the subsequent Monday mornings after the first, second and third weekends were recorded for 90 min.Results: The intraperitoneal administration of GBL caused a rapid onset of bilaterally synchronous SWDs in the cortical EEG accompanied by behavioral immobility, vacant-staring and vibrissal twitching. By repeated GBL injections, animals displayed spontaneous bilateral synchronous SWDs in the baseline EEG on the Monday morning session after the GBL-free weekend period (60 h after the Friday afternoon injection).Conclusion: The present study reports the acute and chronic effects of the systemic administration of GBL. The chronic systemic application of GBL may represent a model of epileptogenesis for absence epilepsy

Absans epilepside gama-butirolakton modeli: wistar sıçanlarda akut ve kronik etkileri

İstanbul Bilim Üniversitesi, Tıp Fakültesi.Objective: We studied the electroencephalographic (EEG) and behavioral changes of the chemical model of generalized absence epilepsy induced by acute and chronic administration of gamma-butrolactone (GBL), a prodrug of gamma-hydroxybutyric acid. Methods: Adult male Wistar rats under anesthesia were implanted with bilateral cortical recording electrodes. The rats were administered 30 intraperitoneal injections of GBL twice daily from Monday to Friday and EEG was recorded 20 min before and 40 min after GBL injections. In order to monitor spontaneous spike-and-wave discharges (SWDs), the baseline EEGs on the subsequent Monday mornings after the first, second and third weekends were recorded for 90 min.Amaç: Çalışmamızda, gama-hidroksibutiratın (GHB) ön ilacı olan gama-butirolakton (GBL) ile indüklenmiş kimyasal jeneralize absans epilepsi modelinde GBL’nin akut ve kronik uygulanmasıyla oluşan EEG ve davranış değişiklikleri incelendi. Gereç ve Yöntem: Çalışmada kullanılan yetişkin Wistar sıçanlara, anestezi altında stereotaksik cerrahi yöntemi uygulandı; hayvanlara iki taraflı kortikal kayıt elektrotları implante edildi. Bir haftalık iyileşme sürecini takiben sabah ve akşam olmak üzere günde iki kez i.p. GBL enjeksiyonu uygulandı. Enjeksiyon uygulamasından önceki 20 dakika, sonrasında 40 dakika olmak üzere EEG kaydı alındı, enjeksiyon yapılmadan geçen haftasonlarını takiben Pazartesi sabahları enjeksiyon öncesi 40 dakika bazal EEG kaydı alındı