The main characteristic of the postnatal development of the stress system in the @entity35 is the so-called stress hypo-responsive period (SHRP). Lasting from postnatal day (pnd) 4 to pnd 14, this period is characterized by very low basal @entity2819 levels and an inability of mild stressors to induce an enhanced ACTH and @entity2819 release. During the last years, the @entity19 has become a generally used animal in stress research, also due to the wide availability of genetically modified @entity19 strains. However, very few data are available on the ontogeny of the stress system in the @entity19 . This study therefore describes the postnatal ontogeny of peripheral and central aspects of the @entity2339 in the @entity19 . We measured ACTH and @entity2819 in blood and @entity8740 , @entity31173 ( @entity31173 ), mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) transcripts in the brain at postnatal days 1, 2, 4, 6, 9, 12, 14 and 16. Our results show that we can subdivide the postnatal development of the @entity2339 in the @entity19 in two phases. The first phase corresponds to the SHRP in the @entity35 and lasts from right after birth (pnd 1) until pnd 12. Basal @entity2819 levels were low and novelty exposure did not enhance @entity2819 or ACTH levels. This period is further characterized by a high expression of @entity8740 in the paraventricular nucleus (PVN) of the hypothalamus. Expression levels of GR in the hippocampus and @entity31173 in the perifornical area are low at birth but increase significantly during the SHRP, both reaching the highest expression level at pnd 12. In the second phase, the @entity19 have developed past the SHRP and were now exhibiting enhanced @entity2819 basal levels and a response of ACTH and @entity2819 to mild novelty stress. @entity8740 expression was decreased significantly, while expression of @entity31173 and GR remained high, with a small decrease at pnd 16. The expression of MR in the hippocampus was very dynamic throughout the postnatal development of the @entity2339 and changed in a time and subregion specific manner. These results demonstrate for the first time the correlation between the postnatal endocrine development of the @entity19 and gene expression changes of central regulators of @entity2339 function.

The postnatal development of the @entity2339 in the XXXX .

@entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity8740 :: ('12918(Tax:10090)', 'Gene') :: ['CRH'] @entity2819 :: ('MESH:D003345', 'Chemical') :: ['corticosterone'] @entity2339 :: ('MESH:D007029', 'Disease') :: ['HPA axis', 'hypothalamic-pituitary-adrenal (HPA) axis'] @entity31173 :: ('83428(Tax:10090)', 'Gene') :: ['urocortin 3', 'UCN3'] @entity35 :: ('10116', 'Species') :: ['rat']
@entity19 :: (10090,Species) :: ['mouse']
