BEHAVIORAL PERFORMANCE OF SWISS-WEBSTER MICE EXPOSED TO EXCESS DIETARY ALUMINUM DURING DEVELOPMENT OR DURING DEVELOPMENT AND AS ADULTS

Swiss Webster mice were exposed to excess dietary aluminum (500 or 1000 mu g Al/g as Al lactate) from conception until weaning or from conception through adulthood (pre- and postweaning). Controls were fed a 7 mu g Al/g diet. Excess Al diets did not influence pregnancy outcome, pup mortality, and body or organ weights. Al diets of 1000 mu g/g led to enhanced cagemate aggression in offspring as adults. At 50 days of age, mice were trained for operant tasks and subsequently 35 sessions of delayed spatial alternation or discrimination reversal testing were conducted. Both the 500 and the 1000 mu g Al/g diets led to faster attainment of criterion during the training phase of the operant studies, but did not influence performance of the two tasks. At the conclusion of the study (150-170 days of age), neurobehavioral measures and tissue trace metals (Al, Fe, Mn) were determined. Both the 500 and the 1000 mu g Al/g diets led to reduced grip strength and the 1000 mu g Al/g diet was associated with lower Fe concentrations in brain and spinal cord. Brain, spinal cord, and liver Al concentrations were elevated only in adults with continued exposure after weaning. Throughout the experiment, mice exposed before and after weaning were apparently no more affected on behavioral measures than those exposed only until weaning. It is concluded that developmental exposure to 500 and the 1000 mu g Al/g diets had distinctive long-term effects on behavioral measures that were not dose dependent and were not further intensified by continuing exposure as adults. (C) 1995 Academic Press, Inc.