PTZ-induced seizures in rats: effects of age and strain.
The susceptibility to pentylenetetrazol (PTZ)-induced seizures during postnatal ontogeny [postnatal day (PN) 10-220] was investigated in two rat strains. The WAG/Rij strain, genetically prone for developing generalized absence epilepsy, and Wistar rats were tested and compared at PN 10, 26, 30, 70, 90, 125, and 220 on the PTZ-convulsive threshold. A subconvulsive dose of 25-mg/kg PTZ was administered every 15 min, and the occurrence of clonic and tonic-clonic seizures was scored. The 10-day-old pups were quite sensitive to PTZ and showed mainly clonic seizures. The highest threshold and latency of PTZ-induced clonic and tonic-clonic convulsions were observed at PN 26 in both strains. From that age onwards, the seizure threshold significantly decreased and reached a minimum at PN 220. Between strain comparisons showed that WAG/Rij rats have a lower tonic-clonic seizure threshold than Wistar rats. The data indicate that changes in susceptibility first quickly decreases until PN 26-30 and then tend to monotonically increase with age, and that genetically prone nonconvulsive WAG/Rij rats are more vulnerable to convulsive seizures induced by PTZ than Wistar rats.
Klioueva
I A
IA
Department of Human and Animal Physiology, Moscow State University, Moscow, Russia.
van Luijtelaar
E L
EL
Chepurnova
N E
NE
Chepurnov
S A
SA
D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000503:physiopathology; D003292:Convulsants / Q000494:pharmacology*; D004830:Epilepsy, Tonic-Clonic / Q000139:chemically induced / Q000473:pathology; D008297:Male; D010433:Pentylenetetrazole / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced* / Q000235:genetics / Q000473:pathology; D013045:Species Specificity
D003292:Convulsants; D010433:Pentylenetetrazole