Ahmed Z, Fellows R E
Department of Physiology, State University of New York, Buffalo 14214.
Brain Res. 1987 Dec 15;465(1-2):77-87. doi: 10.1016/0165-3806(87)90230-6.
The proliferative status and time of origin of dissociated cells from cerebral cortex, basal ganglia, diencephalon, mesencephalon and rhombencephalon of the fetal rat brain have been analyzed. The distributions of cells in different phases of the cell cycle after dissociation and after 7 days in culture have been determined with flow cytofluorometry. Two separate DNA indicators, propidium iodide and Hoechst 33258, have been used. Almost all of the dissociated cells recovered from the 5 brain regions, between embryonic days 15 and 20, are in G1, or growth arrest phase of the cell cycle. In contrast, only about 55% of the liver cells (same fetal age) are in G1, or growth arrest phase. The times of the last in vivo mitoses of the dissociated cells have been determined by maternal injection of [3H]thymidine and autoradiography of cultures. The majority of the cells recovered on embryonic days 16 and 17 from the 5 brain regions appeared to have undergone DNA synthesis within a period of 24 h prior to dissociation. When the fetuses were sacrificed 96 h after the injection, less than 20% of the cells were labelled, and grain density was drastically reduced. Most labelled cells survive in the serum-free culture medium for more than 7 days. Dissociated cultures of synchronized and birth-dated cells from different brain regions of fetal rat should prove particularly useful for the study of cellular development and function.
对胎鼠脑的大脑皮质、基底神经节、间脑、中脑和后脑分离细胞的增殖状态和起源时间进行了分析。采用流式细胞荧光测定法确定了分离后及培养7天后处于细胞周期不同阶段的细胞分布。使用了两种不同的DNA指示剂，碘化丙啶和Hoechst 33258。从胚胎第15天至20天的5个脑区回收的几乎所有分离细胞都处于G1期，即细胞周期的生长停滞期。相比之下，（相同胎龄的）肝细胞只有约55%处于G1期，即生长停滞期。通过母体注射[3H]胸腺嘧啶核苷并对培养物进行放射自显影，确定了分离细胞最后一次体内有丝分裂的时间。从5个脑区在胚胎第16天和17天回收的大多数细胞似乎在分离前24小时内进行了DNA合成。当在注射后96小时处死胎儿时，不到20%的细胞被标记，且银粒密度大幅降低。大多数标记细胞在无血清培养基中存活超过7天。来自胎鼠不同脑区的同步化和出生日期明确的细胞的分离培养物对于细胞发育和功能的研究应特别有用。
