Lifetime lead intoxication: influence on the amygdaloid kindling model of epileptogenesis.

The nature of amygdaloid kindled seizures was studied in adult rats which were intoxicated with lead starting in neonatal life. Lactating females were exposed to lead via the drinking water (0.25% lead acetate) and the litters were continued on this level of lead after weaning at 27 days of age. When compared to controls, levels of lead in the blood and brain were significantly higher in lead-exposed rats, both at the time of weaning as well as postkindling, beyond 150 days of age. Parameters relating to amygdaloid kindled seizures, including the rate of kindling, seizure latency and seizure threshold were not significantly different in lead-treated rats than in controls. However, duration of behavioral seizures and afterdischarges was significantly longer in rats exposed to lead. Our data suggest that, although lead intoxication starting in neonatal life does not appear to affect the susceptibility to development of amygdaloid kindled seizures, it may enhance seizure severity in this model of epileptogenesis.