Suppression of cortical epileptic afterdischarges by ketamine is not stable during ontogenesis in rats.
Anticonvulsant action of ketamine, a noncompetitive NMDA antagonist, was studied in three groups of immature rats (12-, 18-, and 25-day-old) using cortically elicited epileptic afterdischarges (ADs) as a model. Rats with implanted electrodes were used, so that EEG and motor phenomena could be recorded. Stimulation (bipolar pulses of 1-ms duration and 8-Hz frequency) lasting 15 s was repeated four times with intervals of 10 min. Ketamine was administered IP 5 min after the first AD in doses of 5, 10, 20, or 40 mg/kg. Control groups did not receive any drug. Ketamine shortened ADs and suppressed motor correlates of stimulation as well as of ADs in a dose-dependent manner in 12- and 25-day-old rats. No significant changes were observed in 18-day-old animals, demonstrating thus a rather complicated development of anticonvulsant action of ketamine. Not only NMDA antagonism, but also other possible effects of ketamine must be taken into account.
Kubová
H
H
Institute of Physiology, Czechoslovak Academy of Sciences, Prague, Czech Republic.
Mares
P
P
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000254:growth & development* / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000187:drug effects; D004827:Epilepsy / Q000503:physiopathology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D007649:Ketamine / Q000494:pharmacology*; D009068:Movement / Q000187:drug effects; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar
D000927:Anticonvulsants; D018691:Excitatory Amino Acid Antagonists; D016202:N-Methylaspartate; D007649:Ketamine