The effects of early handling on viability of the albino rat.

Abstract

Growing out of Selye''s doctrine of stress, this paper evaluates the hypotheses that early handling raises the threshold for response to stress, thus conserving the metabolic resources of the organism. On the basis of a number of studies Bovard concludes that the effects of early handling are mediated by a permanent alteration in the balance of hypothalamic activity, resulting in increased growth hormone output under normal conditions, and decreased activity of the pituitary-adrenal cortex and sympathetico-adrenal medulla systems under both normal and stress conditions. This alteration in hypothalamic balance is itself the result of change in amygdaloid complex activity, arising from the sensory input from early handling.