Maternal Corticoids During Perinatal Life Influence Hippocampus-Dependent Behavioral and Endocrine Responses in the Adult Rat
Most pharmacological and environmental stimuli able to produce subtle long-term neurochemical and behavioral effects in the offspring also produce hormonal responses in the mother organism, which can propagate to the fetus or newborn through the placenta or milk. In particular, the rat is an excellent model, due to the fact that brain ontogenesis is accomplished during perinatal life, and the stringent dependence upon the mother for maturational processes via hormones and other regulators in the milk. Inducing variations of maternal plasma cor-ticosterone during pregnancy and/or lactation produced neurochemical, endocrine and behavioral effects ascertainable as late as three-four month age. These long-term consequences can be attributed to actions on the ontogenesis and maturation of the hippocampus, hypothalamus, pituitary and adrenals. The hippo-campal glucocorticoid receptor showed permanent variations of the binding capacity, detectable as early as 40 days or as late as 100 days of age. Absence of maternal corticoids during fetal or neonatal life reduced in vitro adrenocortical response to ACTH, and increased in vitro pituitary response to hypothalamic extract.