Behavioral effects following rehabilitation from postnatal exposure to lead acetate

At 21 days of age three groups of male hooded rats of the Sprague-Dawley strain were exposed to either untreated water or lead acetate at concentrations of 25 or 50 ppm provided ad lib. in the drinking water for 40 days. When tested for spontaneous alternation, the subjects receiving both 50 ppm and 25 ppm lead acetate exhibited significantly reduced rates of alternation below those of untreated control subjects. Immediately subsequent to testing, lead was removed from the diet of the experimental groups and water substituted which was provided ad lib. for the duration of the experiment. This regimen of rehabilitation was continued for 70 days at which time all subjects were tested on the problems of the Hebb-Williams closed-field maze-learning task. No significant differences were found in the time taken to traverse the maze enclosure, the number of squares traversed, or in the total number of error zones entered over the 12 test problems, although significantly increased latencies to leave the start box were noted for subjects previously exposed to lead acetate. These data indicate that some deficits produced by postweaning lead acetate exposure may be reversible and not persist beyond a period of rehabilitation.