Impact of Postnatal Manipulations on Offspring Development in Rodents.

In this review we have summarized some of the most common postnatal manipulations designed to mimic in the animal those early environmental experiences that in humans have many implications for the long-term health of the individual. Interestingly, while several studies confirmed the effects of aversive conditions in infancy on later development, there are also strong evidences showing that postnatal manipulations may also exert a protective effect, providing additional stimulation and preparing the animals to face their environment. The outcome of early experiences appears to be tightly linked to genetic predisposition, since it is well known that mouse and rat strains differ for responsiveness to early stimulation, as well as to the amount of maternal care received. At the same time, we emphasized the role of the mother in translating environmental events to her offspring thanks to the epigenetic programming phenomenon, also remarking how events selectively affecting the dam may have long-term consequences on the progeny. We further analyzed the gene-environment interplay by including in our description the cross-fostering paradigm, in which the function of the dam is evaluated by replacing the biological mother with a female with a different phenotype. Finally, we stressed the importance of analyzing the effects of environmental manipulation, not only at adulthood, but also during development. This requires the concomitant evaluation of the mother's and pups' behavior and allows evaluation of mother-infant relationship functioning, as well as detection of malfunctioning or compensatory adaptive behaviors. c15.