Short term lead exposure, age and food deprivation: interactive effects on wheel running behavior of adult male mice.

In three separate experiments, young-adult (75 days old) intermediate-age (220 days old), or older (365 days old) Binghamton Heterogeneous Stock (HET) male mice were maintained on food and either water or a 0.5% lead-acetate drinking solution for only three weeks prior to placement in cages with attached running wheels. Mice were kept on their assigned sources of fluid while in these wheeled cages for six days. On Days 3 and 4 of their 6-day access to the running wheels all mice were deprived of food, but the appropriate drinking fluid remained available continually. Even with this relatively low level of dietary lead exposure, which occurred only during adulthood and immediately prior to (and continued during) the 6-day measurement period, the 48-hour food deprivation challenge differentially altered the wheel running of lead-exposed and control mice; but those effects were apparently altered by the age of the adult mice used in each of the three experiments. These data are discussed in terms of the potency of environmental challenges in revealing behavioral changes related to age and even short-term exposure to environmental/dietary toxicants during adulthood.