Commins D, Yahr P
J Comp Neurol. 1984 Mar 20;224(1):132-40. doi: 10.1002/cne.902240112.
This research shows that the medial preoptic area-anterior hypothalamus (MPOA-AH) of the gerbil contains a sexually dimorphic area (SDA) whose morphology is influenced by adult gonadal steroids. The characteristics of the SDA were studied initially in gonadally intact males and females and later in males and females that had been gonadectomized or gonadectomized and given testosterone. Coronal sections through the MPOA-AH were stained with thionin to visualize the SDA. In male gerbils, the SDA is a darkly staining, hook-shaped structure on either side of the third ventricle, above the suprachiasmatic nuclei and below the anterior commissure. Within the male SDA lies a small, dense cluster of cells, the SDA pars compacta (SDApc). In female gerbils, the SDA is more ovoid and diffuse and the SDApc is absent. Camera lucida tracings and planimeter measurements of the SDA showed that the total volume of the SDA is similar in the two sexes, but the proportion of the SDA that stains darkly and/or stands out clearly from the surround (dark volume) is larger in males. Gonadectomy decreases both total and dark volume of the SDA in both sexes and decreases the volume of the SDApc in males. Testosterone treatment prevents these changes. This is the first report of changes in the gross morphology of the mammalian brain after steroid hormone manipulations in adulthood. The changes in the SDA may be related to testosterone activation of scent marking behavior.
这项研究表明，沙鼠的内侧视前区 - 下丘脑前部（MPOA - AH）包含一个性二态区（SDA），其形态受成年性腺类固醇的影响。最初在性腺完整的雄性和雌性沙鼠中研究了SDA的特征，随后在已切除性腺或切除性腺并给予睾酮的雄性和雌性沙鼠中进行了研究。通过MPOA - AH的冠状切片用硫堇染色以观察SDA。在雄性沙鼠中，SDA是位于第三脑室两侧、视交叉上核上方和前连合下方的深色钩状结构。在雄性SDA内有一小群密集的细胞，即SDA致密部（SDApc）。在雌性沙鼠中，SDA更呈卵形且较弥散，并且不存在SDApc。SDA的明场显微镜绘图和面积测量显示，两性的SDA总体积相似，但雄性中染色深和/或与周围明显区分开的SDA比例（深色体积）更大。去势会降低两性SDA的总体积和深色体积，并减少雄性SDApc的体积。睾酮治疗可防止这些变化。这是关于成年期类固醇激素处理后哺乳动物大脑大体形态变化的首次报告。SDA的变化可能与睾酮对气味标记行为得激活有关。
