Sex differences in cells expressing green fluorescent protein under the control of the estrogen receptor-alpha promoter in the hypothalamus of mice

摘要

Estradiol that originates from testicular testosterone and binds to estrogen receptor-alpha (ER alpha) during developing period acts to organize the male-type brain in mice. Here, we examined transgenic mice expressing green fluorescent protein (GFP) under the control of the ER alpha promoter, in which ER alpha-expressing cells in the brain can be visualized by GFP. Fluorescence microscopy revealed the existence of many GFP-expressing cells in the medial preoptic area, medial preoptic nucleus (MPN), bed nucleus of the stria terminalis (BNST), and striohypothalamic nucleus (StHy) of adult transgenic mice. Neuronal nuclear antigen, a neuron marker, but not glial fibrillary acidic protein, an astrocyte marker, was mostly expressed by GFP-expressing cells. Analysis of GFP expression area showed that adult females had higher GFP expression in a region including the ventral part of the BNST, StHy, and dorsal part of the MPN than in adult males. Such female-biased sex difference was also found in transgenic pups on postnatal day 5 and 8. The GFP expression area of adult females was decreased by postnatal treatment with testosterone or estradiol. These results indicate that GFP visualizes a sex difference of ER alpha-expressing neurons. The transgenic mice may be useful for the analysis of the sexual differentiation of the brain. (C) 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.