Abstract
The brain undergoes substantial growth and refinement during the prenatal and early postnatal periods. As such, early environmental experiences have a substantial impact on brain development and behavior. Maternal care dominates the early environment of most mammals. The impact of maternal care on offspring brain and behavior has been widely studied in laboratory rats. In particular, maternal licking/grooming (LG) provides a critical source of tactile stimulation and has been associated with variation in offspring stress sensitivity, cognition, and neuroendocrine function. Our studies have sought to determine the identity, neuranatomical location, and time‐course of regulation of gene targets associated with these biobehavioral outcomes. In particular, we have focused on how early maternal care (Low vs. High LG) affects the development of two pathways: the hypothalamic estrogen receptor‐alpha (ERα) and mesolimbic dopamine pathways. We have found that as early as one week after birth, hypothalamic levels of ERα diverge in offspring of Low or High LG dams in a site‐specific manner. Maternal LG is also associated with expression of several dopaminergic‐associated factors in the ventral tegmental area by postnatal week 1, and within the nucleus accumbens by postnatal week 3. Epigenetic mechanisms including DNA methylation and histone modification may be underlying these maternally‐induced changes.
Grant Funding Source: NIH