Interaction with stressed mothers affects corticosterone levels in pups after reunion and impairs the response to dexamethasone in adult mice

• Published in: Psychoneuroendocrinology Vol. 33; no. 4; pp. 462 - 470
• Main Authors: Moles, A, Sarli, C, Bartolomucci, A, D’Amato, F.R
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.05.2008; Elsevier
• Subjects: Adrenal Cortex Hormones - blood; Age Factors; Animals; Animals, Newborn - blood; Anxiety; Behavioral psychophysiology; Biological and medical sciences; Corticosterone; Corticosterone - blood; Development; Dexamethasone - pharmacology; Dexamethasone suppression test; Endocrinology & Metabolism; Female; Fundamental and applied biological sciences. Psychology; Glucocorticoids - pharmacology; Hormones and behavior; Hypothalamo-Hypophyseal System - growth & development; Hypothalamo-Hypophyseal System - metabolism; Male; Maternal Behavior - psychology; Maternal Deprivation; Maternal stress; Mice; Mother's behavior; Pituitary-Adrenal System - growth & development; Pituitary-Adrenal System - metabolism; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Social Environment; Stimulation, Chemical; Stress, Psychological - psychology; Maternal stress; Corticosterone; Mother's behavior; Development; Anxiety; Mice; Dexamethasone suppression test; Affect affectivity; Parental behavior; Glucocorticoid; Dexamethasone test; Maternal behavior; Mother; Corticosteroid; Dexamethasone; Steroid hormone; Interaction; Rodentia; Antiinflammatory agent; Stress; Vertebrata; Mammalia; Mouse; Adrenal hormone; Adult animal
• ISSN: 0306-4530; 1873-3360
• DOI: 10.1016/j.psyneuen.2008.01.003

Summary Background Early adverse experiences are preeminent factors for the development of affective disorders. In the present study, we analyzed the effects of different postnatal manipulations applied either on the mother or on the offspring in mice. Maternal behavior and adrenocortical activity of both mothers and offspring at the end of postnatal stress and at adulthood were considered. Methods From postnatal day (PND) 1 to 14 mice underwent 15 min of: (a) brief (15 min) pups’ exposure to clean bedding (CB: clean bedding), (b) mothers’ exposure to the odor of a novel male (SM: stressed mother) or (c) mothers’ exposure to a clean cage (CSM: control stressed mother), and (d) standard rearing (N-H: non-handled). The behavior of mouse dams during and after stress sessions was analyzed. Serum corticosterone of mothers and pups at the end of the stress session and 30 min after reunion was assessed on PND 14. Moreover, anxiety levels and HPA-axis inhibitory feedback in response to dexamethasone administration were evaluated in adult male offspring. Results Overall, during the 14 days of treatment CB mothers when reunited with their pups showed higher maternal behavior than other dams. After the last stress (PND 14) SM and CSM maternal corticosterone levels increased as well as those of CB pups. While 30 min of mother–infant interaction restored baseline corticosterone levels in SM and CSM mothers and in CB pups, SM and CSM offspring showed a decrease of corticosterone under baseline levels. At adulthood, SM and CSM males did not show the suppressive hormonal response to dexamethasone treatment. Moreover, adult CB and SM male mice displayed decreased anxiety in the open field. Conclusions Maternal psychosocial stress during lactation seems to permanently affect the offspring's HPA functioning. These effects may be dissociated from the behavioral response as suggested by the decrease of anxiety in SM and CB adult mice.