title: Systemic focal epileptogenesis.
abstract: Rats that receive radiation to 0.25 cc of one cerebral hemisphere are clinically and electroencephalographically normal until there is a breakdown of the blood-brain barrier (BBB) at 3 to 6 months postradiation. This BBB lesion can be detected by transient focal seizure activity produced by the BBB-excluded systemic convulsant bicuculline methiodide. In two rats the seizure activity induced by this one injection was self-sustaining. In seven of 15 other rats tested, the subsequent administration of repeated 2 mg/kg injections created a chronic focus that continued to spike with great frequency for 3 weeks or more without further administration of any convulsant. In three of eight other rats, implanted minipumps delivering 180 micrograms/h of bicuculline methiodide produced self-sustaining epileptic activity.
mesh_terms: D000818:Animals; D001640:Bicuculline; D001812:Blood-Brain Barrier / Q000528:radiation effects*; D001921:Brain / Q000473:pathology; D004195:Disease Models, Animal; D004569:Electroencephalography; D004827:Epilepsy / Q000209:etiology* / Q000473:pathology; D007696:Kindling, Neurologic; D051381:Rats
chemical_list: D001640:Bicuculline