抄録
In adult female rats, estrogen has crucial effects on the estrus cycle, reproduction and sexual behavior. The hypothalamus is the brain area most obviously related to estrogen actions on these physiological events. Electrophysiologically, it was demonstrated that estrogen exerts different actions between the anterior part containing the preoptic area and the posterior part containing ventromedial hypothalamus. Total RNA was prepared from the anterior and the posterior parts of the hypothalamus of 7 week-old ovariectomized rats after the treatment with estrogen or without the treatment. To evaluate the profile of estrogen responsiveness of genes, total RNA was subjected to cDNA microarray analysis. Based on the results of microarray and quantitative real-time PCR analyses, we selected four neuronal system-related genes, acetylcholine receptor α 4, GABA-A receptor δ , serotonin receptor 6 and GABA transporter 2. In the previous meeting, we presented the estrogen-mediated transcriptional regulation of the four selected genes. The examination of the regulation of these genes at the translational level is now in process by Western-blotting and immunohistochemistry. Recently, we obtained results that the expression of the acetylcholine receptor α 4 protein differed depending on the area of the hypothalamus and the time of exposure to estrogen. We present here the recent results and discuss the molecular bases for the site- and time-specific regulation of neuronal system-related genes in the hypothalamus by estrogen. [J Physiol Sci. 2006;56 Suppl:S217]
