Neonatal footshock stress alters adult behavior and hippocampal corticosteroid receptors

To determine the effects of stress early in life on adult behavior and hipp ocampal corticosteroid receptors, rats were exposed to footshocks (0.8 mA, 60 times/day, randomly apart) on postnatal days 14, 17 and 20. When they re ached 6 months of age, neurobehavioral alterations were measured. The foots hock-experienced rats learned more rapidly in the autoshaped learning test than similarly handled controls. They also stabilized more quickly after ex posure to a novel environment than the handled controls, but only at the sa me rate as animals which had not been handled except for weighing. The dens ity of [H-3]dexamethasone binding sites increased and that of [H-3]corticos terone binding sites decreased in the hippocampi of these rats. These resul ts indicate that early life stress results in altered behavior and hippocam pal corticosteroid receptors at adulthood, and suggest that the mineralocor ticoid and the glucocorticoid receptors are differentially regulated by ear ly life stress. (C) 1999 Lippincott Williams & Wilkins.