Long-Lasting Effects of Chemical Exposures in Mice

Abstract

Genetically inbred strains of mice provide an excellent model for the study of normal variation in olfaction and for evaluating how sensitivity to odorants can be modulated by environmental exposures. Using two inbred strains, one quite sensitive to androstenone (CBA/J) and the other (NZB/B1NJ) insensitive to the odorant, we have been exploring both genetic and environmental contributions to variation in olfaction. Herein we present behavioral and biochemical correlates of the effects of exposures to androstenone during different times in the development of young mice and we explore some long-lasting effects of such exposures. Although exposures to androstenone per se induce sensitization to the compound, exposures during days 14-28 of age appear to maximize such effects. Furthermore, the effects of early exposures on behavioral sensitivity were noted in mice that were over 8 months old (comparable to a human beyond mid-life). Biochemical changes in the sensory epithelia also were noted: Here too, the effects were long-lasting. These results suggest that, although genetics may limit or set boundaries upon emergent potential, early exposures to odorants may have direct, long-lasting impact upon the sensory apparatus and its central nervous system (CNS) connections, and hence upon the behavior of individuals.