Distribution of estrogen receptors in the brain of the Japanese quail: an immunocytochemical study

Abstract

The distribution of estrogen receptors in the quail brain was investigated by immunocytochemistry using the monoclonal antibody H222SPy raised against estrogen receptors that had been isolated from a human mammary tumor. Nuclei which contained cells labeled for estrogen receptor were identified in the telencephalon, diencephalon and mesencephalon. In particular, a high percentage of labeled cells was observed in the lateral septum, the nucleus accumbens, the preoptic medial nucleus, the suproptic nuclei, the anterior medial hypothalamus, the paraventricular magnocellular nucleus, the caudal parts of the lateral hypothalamus and in the whole tuberal and infundibular area. A small number of weakly labeled cells was also observed in the ventromedial nucleus of the hypothalamus. Although most of the positive cells were observed in the hypothalamic and preoptic area, a few areas were also labeled in other brain regions. This was particularly the case for the nucleus intercollicularis and the central gray. The distribution of labeled cells in this study closely matched with the distribution of cells which accumulated radioactivity following injection of tritiated estradiol in a previous study. The distribution of cells labeled by immunocytochemistry was similar in males and females and no evidence for a quantitative dimorphism in the percentage of labeled cells could be obtained. All nuclei containing cells labeled for estrogen receptors also contain significant levels of aromatase with the exception of the ICo.