Jacobson C D, Davis F C, Gorski R A
Brain Res. 1985 Jul;353(1):7-18. doi: 10.1016/0165-3806(85)90019-7.
The sexually dimorphic nucleus of the preoptic area (SDN-POA) appears to be a morphological marker of the process of sexual differentiation of the rat brain. A portion of the presumptive SDN-POA neurons can be specifically identified utilizing autoradiography following the administration of [3H]thymidine on day 18 of gestation. In the present study we have utilized this fact in order to describe the general pattern of formation of the SDN-POA during the perinatal period. Following the administration of [3H]thymidine, fetal pups were sacrificed and perfused with neutral formalin either two hours after the injection or on day 20 or 22 postfertilization. Neonatal pups were either sacrificed and perfused or assigned to one of the treatment groups. Male pups were either gonadectomized or sham gonadectomized; females were all sham gonadectomized. These pups were then sacrificed and perfused on either day 26, 28 or 32 postfertilization. All brains were processed for autoradiography. The size, number and location of labeled cells within the medial preoptic area (MPOA) was determined. In general it appears that the labeled cells grow in size during the early postnatal period. These cells also migrate from the more ventral aspects of the MPOA to aggregate and form the SDN-POA. Furthermore, there is a significant decrease in the number of labeled cells by day 32 postfertilization (day 10 of postnatal life) which appears to contribute to the specific labeling of the SDN-POA of the adult animal. However, results obtained in this study from quantitative analyses do not indicate that sex or the postnatal steroid hormone environment influence the processes of growth, migration and decrease in MPOA cell number of those presumptive SDN-POA cells born specifically on day 18 of gestation and analyzed in this study.
视前区性二态核（SDN-POA）似乎是大鼠脑性分化过程的一个形态学标志。在妊娠第18天给予[3H]胸腺嘧啶核苷后，利用放射自显影技术可特异性地识别一部分推测的SDN-POA神经元。在本研究中，我们利用这一事实来描述围产期SDN-POA的一般形成模式。给予[3H]胸腺嘧啶核苷后，在注射后两小时或受精后第20天或第22天处死胎鼠并用中性福尔马林灌注。新生幼鼠要么被处死并灌注，要么被分配到一个治疗组。雄性幼鼠要么进行性腺切除，要么进行假性腺切除；雌性幼鼠均进行假性腺切除。然后在受精后第26、28或32天处死并灌注这些幼鼠。所有大脑均进行放射自显影处理。确定内侧视前区（MPOA）内标记细胞的大小、数量和位置。一般来说，标记细胞在出生后早期体积增大。这些细胞也从MPOA更靠腹侧的部位迁移，聚集并形成SDN-POA。此外，在受精后第32天（出生后第10天）标记细胞数量显著减少，这似乎有助于成年动物SDN-POA的特异性标记。然而，本研究中定量分析的结果并未表明性别或出生后的类固醇激素环境会影响那些在妊娠第18天特异性出生并在本研究中分析的推测的SDN-POA细胞在MPOA中的生长、迁移和数量减少过程。
