Anticonvulsive effect of urethane on aminopyridine-induced epileptiform activity.
The effects of urethane anaesthesia on the development and spread of ictal-like epileptiform activity induced by 3-aminopyridine, was investigated on the somatosensory cortex of rats. Under urethane anaesthesia in most animals only one abortive ictal period appeared with dose-dependent latency. Urethane completely abolished high frequency afterdischarges (5-10 Hz) and prevented the development of recurrent seizures in both primary and mirror foci. Urethane also eliminated ongoing epileptiform activity induced previously by 3-aminopyridine under nembutal anaesthesia. The antiepileptic effects of urethane on ictal-like activity may be the consequence of a presynaptic action through reduction of glutamate-mediated excitation together with a depressant effect on responsiveness of cortical neurones. The afterdischarges of high frequency could be essential to development and stabilization of repetitive tonic events in the neocortex.
Heltovics
G
G
Department of Comparative Physiology, Attila József University, Szeged, Hungary.
Boda
B
B
Szente
M
M
D000631:Aminopyridines; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004827:Epilepsy / Q000139:chemically induced* / Q000517:prevention & control*; D005260:Female; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000187:drug effects* / Q000502:physiology; D014520:Urethane / Q000494:pharmacology*
D000631:Aminopyridines; D014520:Urethane