title: An isolated epileptic seizure elicits learning impairment which could be prevented by melatonin.
abstract: We tested the relation between a single short tonic-clonic seizure elicited by flurothyl vapors and changes of learning in Morris water maze (MWM) in Wistar rats. Oxidative stress usually accompanies seizures. Large melatonin doses were applied immediately before and after seizures to test consequences on learning impairment. One hour of hypobaric hypoxia (8000 m) three days prior to the seizure served as an activator of intrinsic antioxidant systems. Learning in MWM (7 days) started 24 h after seizures. Following seizures, latencies in MWM were longer than in controls and were shortened by hypoxia and preventive melatonin application. Melatonin was also applied before hypoxia to influence free radical (FR) production and intrinsic antioxidant activation. Some behavioral characteristics were changed and preconditioning effect of hypoxia was reduced. Melatonin after seizure (150 s and 6 h) had negligible effect. Results allow us to hypothesize about the role of FR and the beneficial effect of melatonin on the behavioral consequences of seizures.
authors.affiliation: Charles University in Prague, Third Faculty of Medicine, Department of Normal, Pathological and Clinical Physiology, Czech Republic. jan.mares@lf3.cuni.cz
authors.forename: Jan
authors.initials: J
authors.lastname: Mareš
authors.forename: Marie
authors.initials: M
authors.lastname: Pometlová
authors.forename: Kateryna
authors.initials: K
authors.lastname: Deykun
authors.forename: David
authors.initials: D
authors.lastname: Krýsl
authors.forename: Richard
authors.initials: R
authors.lastname: Rokyta
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001332:Automatism / Q000209:etiology / Q000517:prevention & control; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000503:physiopathology; D003292:Convulsants / Q000633:toxicity; D004195:Disease Models, Animal; D005481:Flurothyl / Q000633:toxicity; D000860:Hypoxia / Q000150:complications; D007859:Learning Disabilities / Q000209:etiology* / Q000517:prevention & control*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008550:Melatonin / Q000627:therapeutic use*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D012640:Seizures / Q000139:chemically induced / Q000150:complications* / Q000473:pathology; D013997:Time Factors
chemical_list: D000975:Antioxidants; D003292:Convulsants; D005481:Flurothyl; D008550:Melatonin