Ontogeny of spontaneous petit mal-like seizures in Wistar rats.

Wistar rats spontaneously presenting electroclinical signs of petit mal-like epileptic seizures were inbred until all offspring were affected, and the ontogeny of this inherited phenotype was studied in the offspring from 30-60 days of age to 18 months. The first EEG spike and wave discharges appeared at 40-120 days. Their number and duration increased progressively with age.