Susceptibility to focal and generalized seizures in Wistar rats with genetic absence-like epilepsy

• Published in: Neuroscience Vol. 93; no. 3; pp. 1173 - 1177
• Main Authors: Brailowsky, S., Montiel, T., Boehrer, A., Marescaux, C., Vergnes, M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.1999; Elsevier
• Subjects: absence epilepsy; Animals; Biological and medical sciences; cerebral cortex; Convulsants - toxicity; Electroencephalography; Epilepsies, Partial - chemically induced; Epilepsies, Partial - genetics; Epilepsy, Absence - genetics; Epilepsy, Generalized - chemically induced; Epilepsy, Generalized - genetics; focal epileptogenesis; GABA-withdrawal syndrome; gamma-Aminobutyric Acid - toxicity; Genetic Predisposition to Disease; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; pentylenetetrazol; Pentylenetetrazole - toxicity; Rats; Rats, Mutant Strains - genetics; Rats, Wistar; GAERS, Genetic Absence Epilepsy Rat from Strasbourg; SWD, spike-and-wave discharge; absence epilepsy; cerebral cortex; pentylenetetrazol; NEC, non-epileptic control; EEG, electroencephalogram; focal epileptogenesis; GWS, GABA-withdrawal syndrome; GABA-withdrawal syndrome; UNAM, Universidad Nacional Autónoma de México; Nervous system diseases; Cerebral cortex; Pentetrazol; Rat; Weaning; Epilepsy; Rodentia; Central nervous system; Petit mal; Cerebral disorder; Vertebrata; Sensitivity; Mammalia; Animal; Central nervous system disease; Neurotransmitter; GABA; Brain (vertebrata)
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(99)00227-4

The susceptibility to develop cortically induced focal and generalized seizures was examined in Genetic Absence Epilepsy Rats from Strasbourg (GAERS), an inbred strain of Wistar rats with absence epilepsy. A GABA-withdrawal syndrome induced after suppression of a 2-h intracortical GABA infusion was used as a model of focal epileptogenesis: localized cortical discharges appear at the infusion site within 1 h. GAERS were more prone to develop a GABA-withdrawal syndrome than non-epileptic inbred controls and non-selected Wistar rats. After a transient suppression of absence seizures following GABA infusion in GAERS, generalized spike-and-wave discharges and focal spikes were recorded simultaneously in the cortex. GAERS also showed a higher incidence of systemic pentylenetetrazol-induced convulsions at the dose of 25 mg/kg. Higher doses had similar convulsant effects in all groups. In conclusion, the results confirm a genetic susceptibility in GAERS and/or resistance in inbred non-epileptic rats to focal and generalized seizures involving the cortex. Rats with absence epilepsy appear to be more prone to seizures elicited by cortical GABA deficiency.