Minimal behavioral effects from moderate postnatal lead treatment in rats

Developmental lead exposure continues to be a worldwide problem. This study investigated the behavioral effects resulting from developmental lead treatment in rats with corresponding physiological measures of lead exposure. Sprague-Dawley rats were treated with 350 ppm lead acetate from birth to weaning via the dam's drinking water. Behavioral measures assessed in the offspring included residential activity tests, complex maze performance, acoustic startle response, emergence behavior (light/dark preference), prepulse inhibition, and ethological assessments of play, dominance, and burrowing. Pb blood levels averaged 53 microg/dl in the dam at the time of offspring weaning and 46 microg/dl in weanling female offspring. Pb levels averaged 277 ng/g and 32 microg/g in the brain and bone, respectively, of female offspring at weaning. No behavioral assessment indicated any lead-related functional alterations nor were there any statistically significant differences when the lead-treated group was restricted to rats in those litters that were above the median Pb blood lead level at weaning. These results indicate that any lead-related functional alterations at this dose may be subtle and require a sufficient demand on the system for detection.