The hypothalamo-pituitary-adrenal (HPA) @entity2270 plays important roles in the adaptive changes in physiology that occur during pregnancy and lactation. Although the @entity2270 still exhibits a pulsatile pattern of secretion, the normal diurnal rhythm of pulse amplitude is lost during lactation, such that mean basal levels remain constant throughout the day. In addition, the peripartum period is associated with a remarkable plasticity in stress-induced HPA activity, in that the increase of HPA activity normally seen in response to either physical or psychological stresses in the non-reproductive state become severely attenuated or absent in the lactating animal. This stabilization of both basal and stress-induced HPA activity may be important for maintaining a constant endocrine environment, thereby preventing any programming effects on the developing offspring. Attenuation of the stress response is initiated in late pregnancy and is temporally associated with luteolysis, indicating possible @entity134 hormone involvement. Indeed, mimicking the luteolytic changes in @entity2931 and @entity1420 levels in non-pregnant animals induces a similar attenuation of the stress response. Furthermore down-regulation of the stress response is, at least in part, centrally mediated since in the period following luteolysis @entity35 will show a decreased level of stress-induced neuronal activation of the PVN, as measured by the expression of either @entity5019 or @entity3318 mRNAs. Persistence of this adapted state is dependent upon the continued suckling stimulus, as removal of the offspring litter rapidly leads to resumption of HPA responses to and the appearance of an exaggerated diurnal rhythm. The underlying mechanisms responsible for this stress @entity6306 may include plasticity of noradrenergic and @entity398 pathways. In view of its role in other reproductive behaviors, a stress-inhibiting effect of @entity398 may reflect a more widespread co-ordinating role in the peripartum animal.

Peripartum plasticity within the hypothalamo-pituitary-adrenal XXXX .

@entity398 :: ('MESH:D010121', 'Chemical') :: ['oxytocin'] @entity6306 :: ('MESH:C566417', 'Disease') :: ['hyporesponsiveness'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity1420 :: ('MESH:D011374', 'Chemical') :: ['progesterone'] @entity2931 :: ('CHEBI:50114', 'Chemical') :: ['oestrogen'] @entity5019 :: ('314322(Tax:10116)', 'Gene') :: ['c-fos'] @entity134 :: ('CHEBI:35341', 'Chemical') :: ['steroid'] @entity3318 :: ('81648(Tax:10116)', 'Gene') :: ['CRH'] @entity2270 :: ('MESH:C566610', 'Disease') :: ['axis']
@entity2270 :: (MESH:C566610,Disease) :: ['axis']
