Gibbs R B
Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, PA 15261, USA.
Brain Res. 1996 May 13;720(1-2):61-8. doi: 10.1016/0006-8993(96)00106-0.
Recent studies have demonstrated that estrogen administration can produce significant increases in relative levels of choline acetyltransferase (ChAT) mRNA and protein in specific regions of the female, but not the male, rat basal forebrain. In the present study immunocytochemical techniques were used to identify and compare relative numbers of cholinergic neurons containing estrogen receptors within the medial septum, horizontal limb of the diagonal band of Broca, nucleus basalis magnocellularis, and striatum of gonadectomized male and female rats to determine whether there are differences in the percentage of cholinergic neurons expressing estrogen receptors which might contribute to the different regional- and sex-specific effects of estrogen which have been described. Counts of choline acetyltransferase-immunoreactive cells revealed significant regional differences in the average number of cholinergic neurons/section; however, no difference between males and females in the numbers of cholinergic neurons in each of the four regions analyzed was observed. Fifty to eighty percent of the cholinergic neurons detected in both males and females contained estrogen receptor-like immunoreactivity. A small but significant difference between males and females was detected with females having slightly more (10.5%) double-labeled cells than males overall. Individual comparisons revealed that significantly more (18-33%) double-labeled cells were detected in the horizontal limb of the diagonal band, but not in the medial septum, nucleus basalis, or striatum of females vs. males. There was also a small but significant regional difference in the percentage of double-labeled cells with the highest percentage (74.2%) detected in the striatum and the lowest percentage (63.4%) detected in the horizontal limb. None of these differences appear to account for the regional- and sex-specific effects of estrogen on cholinergic neurons which have been observed. We conclude that differences in the effects of estrogen on cholinergic neurons in males vs. females and in different subregions of the female basal forebrain are not due to differences in the percentage of cholinergic neurons expressing estrogen receptors.
近期研究表明，给予雌激素可使雌性而非雄性大鼠基底前脑特定区域内胆碱乙酰转移酶（ChAT）mRNA和蛋白质的相对水平显著升高。在本研究中，运用免疫细胞化学技术鉴定并比较去势雄性和雌性大鼠内侧隔核、布罗卡斜角带水平支、基底大细胞核及纹状体内含有雌激素受体的胆碱能神经元的相对数量，以确定表达雌激素受体的胆碱能神经元百分比是否存在差异，这可能有助于解释已描述的雌激素在区域和性别上的特异性作用。胆碱乙酰转移酶免疫反应性细胞计数显示，胆碱能神经元的平均数量/切片存在显著的区域差异；然而，在所分析的四个区域中，未观察到雄性和雌性胆碱能神经元数量的差异。在雄性和雌性中检测到的胆碱能神经元有50%至80%含有雌激素受体样免疫反应性。检测到雄性和雌性之间存在微小但显著的差异，总体而言，雌性的双标记细胞略多（10.5%）。个体比较显示，与雄性相比，在雌性的斜角带水平支中检测到显著更多（18% - 33%）的双标记细胞，但在内侧隔核、基底核或纹状体中未检测到。双标记细胞的百分比也存在微小但显著的区域差异，纹状体中检测到的百分比最高（74.2%），斜角带水平支中检测到的百分比最低（63.4%）。这些差异似乎都无法解释已观察到的雌激素对胆碱能神经元的区域和性别特异性作用。我们得出结论，雌激素对雄性和雌性胆碱能神经元以及雌性基底前脑不同亚区域作用的差异并非由于表达雌激素受体的胆碱能神经元百分比的差异。
