[Functional role of adrenocorticotropin in the postnatal ontogenesis of rats].

It has been demonstrated by radioimmunoassay that blood ACTH content in young rats substantially rises during eye opening, maximal motor activity, and formation of the vegetative component of the orientation research activity. Under the conditions of an "open field", adrenocorticotropic activity in young rats increases to a greater degree than that in adult animals. This is especially demonstrable during the period of the maximal motor activity (day 16 of postnatal ontogenesis) and the period of nesting completion (day 28). It is concluded that ACTH plays an important functional role in the organization of the adaptive behavior in postnatal ontogenesis of rats.