Kainic acid neurotoxicity and seizures

Abstract

The effects of anesthetics and anticonvulsants on the neurotoxic effects of kainic acid (2.3 nmol) injected into the rat hippocampus and striatum have been examined with regard to neurochemical, histological and electroencephalographic alterations. Brief anesthesia with ether resulted in seizures and severe degeneration of the hippocampal CA 1−4 pyramids and granule cells. Prolonged anesthesia (> 300 min) with chloral hydrate-pentobarbital or with γ-butyrolactone protected most hippocampal neurons and blocked seizures. Phenobarbital (100 mg/kg) prevented cortical seizures but provided minimal protection against hippocampal neuronal degeneration. Prolonged anesthesia (> 300 min) with chloral hydrate-pentobarbital also attenuated the neurotoxic effects of kainic acid in the striatum. The anesthetic and not the anticonvulsant action of drugs accounted for the protection against the neurotoxicity of kainic acid at the site of injection.