Abstract
The effects of neonatal vitamin A exposure on six behavioral parameters in adult Wistar rats were investigated. Newborn male rats were injected intraperitoneally with 80, 000 IU/kg/day of retinol palmitate (vitamin A) dissolved in physiological saline or vehicle alone (controls) during 1-5 days after birth. The animals were examined using the open field test (at 36 weeks of age), the rotarod test (38 weeks), the Biel water-maze test (40 weeks), the conditioned avoidance test (42 weeks), the running-wheel activity with pentobarbital challenge test (44 weeks), and the tail flick test (45 weeks). The vitamin A-exposed rats made significantly more errors and took significantly longer times in the Biel water-maze test, and showed significantly slower responses in the tail flick test than the controls. No significant effects of treatment with vitamin A were observed in any of the other behavioral tests. These results indicate that a long-lasting defect in learning in water-maze task and depression of the heat-pain response are induced in rats exposed neonatally to vitamin A.
