Open AccessSex differences in progesterone receptor immunoreactivity in neonatal mouse brain depend on estrogen receptor α expression
Author(s) -
Wagner Christine K.,
Pfau Jennifer L.,
De Vries Geert J.,
Merchenthaler Istvan J.
Publication year - 2001
Publication title -
journal of neurobiology
Language(s) - English
Resource type - Journals
eISSN - 1097-4695
pISSN - 0022-3034
DOI - 10.1002/neu.1025
Subject(s) - biology , medicine , endocrinology , neocortex , estrogen receptor alpha , estrogen receptor , estrogen , alpha (finance) , sexual differentiation , receptor , progesterone receptor , hormone , gene , neuroscience , genetics , construct validity , cancer , breast cancer , nursing , patient satisfaction
Abstract Around the time of birth, male rats express higher levels of progesterone receptors in the medial preoptic nucleus (MPN) than female rats, suggesting that the MPN may be differentially sensitive to maternal hormones in developing males and females. Preliminary evidence suggests that this sex difference depends on the activation of estrogen receptors around birth. To test whether estrogen receptor alpha (ERα) is involved, we compared progesterone receptor immunoreactivity (PRir) in the brains of male and female neonatal mice that lacked a functional ERα gene or were wild type for the disrupted gene. We demonstrate that males express much higher levels of PRir in the MPN and the ventromedial nucleus of the neonatal mouse brain than females, and that PRir expression is dependent on the expression of ERα in these regions. In contrast, PRir levels in neocortex are not altered by ERα gene disruption. The results of this study suggest that the induction of PR via ERα may render specific regions of the developing male brain more sensitive to progesterone than the developing female brain, and may thereby underlie sexual differentiation of these regions. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 176–182, 2001