Foster litters prevent hypothalamic-pituitary-adrenal axis sensitization mediated by neonatal maternal separation.
Psychoneuroendocrinology
; 29(2): 279-89, 2004 Feb.
Article
em En
| MEDLINE
| ID: mdl-14604606
ABSTRACT
Neonatal maternal separation of rat pups has been shown to produce long-term increases in hypothalamic-pituitary-adrenal (HPA) axis responsiveness, elevated levels of hypothalamic corticotropin releasing factor (CRF) mRNA in the hypothalamic paraventricular nucleus (PVN), and enhanced anxiety-like behavior. These effects appear to be at least partially mediated by subtle disruptions in the quality of maternal-pup interactions. This hypothesis was tested by providing half the dams with foster litters during the maternal separation paradigm, so that in those litters, only the pups and not the dams were experiencing a period of separation. The separation protocol took place daily from PND2-14 for either 15 min (HMS15, handled) or 180 min (HMS180, maternal separation). During the period of separation dams were either transferred to adjacent cages without any pups present (HMS15, HMS180) or to cages containing an age-matched foster litter (HMS15F, HMS180F). As adults, the HMS180 progeny exhibited the expected increased expression of CRF mRNA in the PVN, stress hyper-responsiveness to airpuff startle and evidence of impaired feedback both in the CORT response, as well as in response to the dexamethasone suppression test. The HMS180F rats, however, appeared to be resistant to these effects of maternal separation as they demonstrated CRF mRNA levels intermediate between HMS15 and HMS180 rats. Their stress responses and feedback regulation of the HPA axis was comparable to that of the HMS15 rats. GR mRNA was elevated in the cortex of HMS180F rats. Overall, these studies support the thesis that the long-term effects of neonatal maternal separation may largely result from alterations in the quality of maternal care rather than from direct effects of the separation per se on the pups.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sistema Hipófise-Suprarrenal
/
Estresse Psicológico
/
Glucocorticoides
/
Sistema Hipotálamo-Hipofisário
/
Privação Materna
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Psychoneuroendocrinology
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos