Effects of prenatal aflatoxin B-1 exposure on behaviors of rat offspring

The effects of prenatal aflatoxin B-1 (AFB) exposure on eight behavioral pa rameters in Jc1:Wistar rat offspring were assessed. Pregnant rats were inje cted subcutaneously with 0.3 mg/kg/day of AFB dissolved in dimethylsulfoxid e on days 11-14 (Group A) or 15-18 (Group B) of gestation. Controls receive d the vehicle similarly on days 11-18 of gestation. Before weaning, the off spring were examined using the cliff avoidance response (5 days of age), th e negative geotaxis reflex (7 days), and swimming development (6, 8, and 10 days). After weaning, animals were examined using the rotarod test (5 week s of age), the open field test (6 weeks), a conditioned avoidance learning test (14 weeks), an underwater T-maze test (15 weeks), and a reproduction t est (16 weeks). The preweaning offspring in the AFB-A group showed signific antly lower success rates than controls in cliff avoidance responses. In sw imming development, the offspring in the AFB-A group had significantly lowe r scores than controls for swimming direction. In the rotarod test, the AFB -A group remained on the rod for a significantly shorter time than the cont rols at 15 rpm on both the first and second trial days. The avoidance perfo rmance of the rats in AFB-A and AFB -B groups was significantly poorer than that of controls. These results indicate that prenatal exposure to AFB pro duced a delay of early response development, impaired locomotor coordinatio n, and impaired learning ability in the offspring of rats exposed to AFB du ring middle pregnancy, and the early gestational exposure appears to produc e more effects than latter exposure.