EVIDENCE FOR INCREASED SEIZURE SUSCEPTIBILITY IN RATS EXPOSED TO COCAINE IN-UTERO

Clinical observations indicate that cocaine use during pregnancy is a major health concern in the United States and may result in seizure-li ke behavior in the offspring. In the present study, we investigated wh ether prenatal cocaine exposure altered seizure thresholds measured in Sprague-Dawley rats, 60-90 days postnatal. In vitro postnatal studies , focusing on hippocampal tissue, revealed a reduced threshold for bot h electrical stimulation-and potassium-induced epileptiform discharges in slices from cocaine-exposed animals. Modest elevation of extracell ular potassium concentration from 3 to 6 mM KCl elicited spontaneous e pileptiform discharges in the majority of slices from cocaine-exposed animals (13/20) but rarely in slices from saline-exposed animals (2/18 ). In vivo studies on awake, freely behaving adult rats indicated a si gnificant reduction in thresholds for both flurothyl-and kainic acid-i nduced seizures in cocaine-exposed animals. Video-EEG monitoring durin g administration of kainic acid revealed reduced latencies to first 'e lectrographic seizure' and first 'electrographic seizure with behavior ' in rats exposed to cocaine in utero compared to saline-treated contr ols. These studies provide strong experimental evidence that adult ani mals exposed to cocaine during gestation are at high risk for the deve lopment of seizure activity. (C) 1997 Elsevier Science B.V.