MATERNAL-CARE, HIPPOCAMPAL GLUCOCORTICOID RECEPTORS, AND HYPOTHALAMIC-PITUITARY-ADRENAL RESPONSES TO STRESS

Variations in maternal care affect the development of individual diffe rences in neuroen-docrine responses to stress in rats. As adults, the offspring of mothers that exhibited more licking and grooming of pups during the first 10 days of life showed reduced plasma adrenocorticotr opic hormone and corticosterone responses to acute stress, increased h ippocampal glucocorticoid receptor messenger RNA expression, enhanced glucocorticoid feedback sensitivity, and decreased levels of hypothala mic corticotropin-releasing hormone messenger RNA. Each measure was si gnificantly correlated with the frequency of maternal licking and groo ming (all r's > -0.6). These findings suggest that maternal behavior s erves to ''program'' hypothalamic-pituitary-adrenal responses to stres s in the offspring.