Anticonvulsant effects of melatonin on penicillin-induced epileptiform activity in rats.
In the present study, we investigated the effects of melatonin on penicillin-induced epileptiform activity in female Wistar rats. The left cerebral cortex was exposed by craniotomy under urethane anesthesia for the induction of epilepsy by intracortical microinjection of penicillin (200 IU) into the left sensorimotor cortex. The epileptiform activity was analyzed by electrocorticogram (ECoG). Ten minutes before the penicillin injection, 20, 40 or 80 microg of melatonin was administered intracerebroventricularly and ECoG was monitored for 1 h. Forty or 80 microg of melatonin significantly increased the latency to epileptiform activity. Furthermore, melatonin significantly decreased the frequency of spike and spike-wave activity, whereas the amplitude of spikes remained unchanged. In conclusion, data obtained from the present study suggest that melatonin suppresses penicillin-induced epileptiform activity, and it may be an endogenous anticonvulsant.
Yildirim
Mehmet
M
Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey. mehmetyd@omu.edu.tr
Marangoz
Cafer
C
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000379:methods; D004827:Epilepsy / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D008550:Melatonin / Q000627:therapeutic use*; D010406:Penicillins; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D013003:Somatosensory Cortex / Q000187:drug effects / Q000503:physiopathology
D000927:Anticonvulsants; D010406:Penicillins; D008550:Melatonin