Prenatal Morphine Exposure Alters N-Methyl- d-Aspartate- and Kainate-Induced Seizures in Adult Male Rats

Abstract

ŠLAMBEROVÁ, R., L. VELÍŠEK AND I. VATHY. Prenatal morphine exposure alters N- methyl- d -aspartate- and kainate-induced seizures in adult male rats. PHARMACOL BIOCHEM BEHAV 65(1) 39–42, 2000 .—The purpose of the present study was to investigate whether prenatal exposure to morphine has effects on excitatory amino acid-induced seizures. Adult male rats, exposed on embryonic days 11–18 to saline or morphine, were injected with N-methyl- d -aspartate (NMDA) (150, 175, 200, 225, and 250 mg/kg) or kainic acid (KA) (15 or 20 mg/kg) in adulthood to assess the occurrence and latency to onset of stereotypy and seizures. The latency to onset of stereotypy was significantly increased after 175 mg/kg, and decreased after 200 mg/kg of NMDA in morphine-exposed animals. The lowest dose of NMDA (150 mg/kg) induced seizures in prenatally saline-treated control male rats but not in the morphine-exposed male rats. In the KA-injected group, prenatally morphine-exposed males had shorter latency to onset of wet-dog shakes, but there were no effects on the latency to onset of clonic seizures. The data suggest that prenatal morphine exposure has long-term effects on seizure susceptibility and the onset of stereotypy in the excitatory amino acid-induced seizure models.