The blood-brain barrier lesion and the systemic convulsant model of epilepsy.
Systemic kainic acid (KA) at 1 mg/kg crosses the normal blood-brain barrier (BBB) of rats to produce scattered sharp waves for approximately 10 min on the EEG, but is without observable effect, producing no EEG or behavioral changes, at 0.5 mg/kg. When the BBB is opened in most of one hemisphere by 6,000 rads, the rats are clinically normal and have a normal EEG. When the irradiated rats are challenged with 0.5 mg/kg KA, intense, highly lateralized epileptiform bursts result; these bursts last 1-10 s and recur for 90 mins. This phenomenon is repeatable for the 1 week that the BBB is open. The results are identical when the BBB is opened with a pin lesion. Because endogenous glutamate agonists are common, these data suggest a possible pathophysiologic mechanism for human epilepsy.
D000818:Animals; D001812:Blood-Brain Barrier / Q000528:radiation effects; D004828:Epilepsies, Partial / Q000139:chemically induced*; D007608:Kainic Acid / Q000008:administration & dosage; D008954:Models, Biological; D011759:Pyrrolidines / Q000008:administration & dosage; D051381:Rats; D012377:Rodentia
D011759:Pyrrolidines; D007608:Kainic Acid