ABSTRACT
INTRODUCTION Behavioral phenotyping is used to evaluate the functional consequences of exposure to chemicals, drugs, environmental contaminants or nutrients on the health, as well as on the refl ex, sensory, motor, social, and cognitive repertoire of mice. Most frequently, studies query the effects of acute exposures on the behavior of adult animals, either immediately or across aging. Developmental neurotoxicity studies typically expose the embryo and/or fetus via the dam in utero, followed by continued exposure through lactation until weaning. Behavioral effects in the offspring often are measured only after sexual maturity, beginning at about 60 days of age, or in young and mature adults. In each of these cases, adult test batteries are employed. However, where the questions relate to the effect of substance exposures on the ontogeny of behavioral development, testing during the neonatal and pre-pubescent periods is necessary. Test strategies for neonatal mice must address a rapidly changing behavioral repertoire as well as effects of the birth and rearing litter.
