Wierzba-Bobrowicz T, Lewandowska E, Schmidt-Sidor B, Gwiazda E
Department of Neuropathology, Institute of Psychiatry and Neurology, Warszawa.
Folia Neuropathol. 1999;37(4):227-34.
The study was performed on the tissues derived from the central nervous system (CNS) of 72 normal human fetuses between 8 and 22 week of gestation (GW) and 30 fetuses with genetically confirmed Down's syndrome between 17 and 22 GW. Histochemical, immunocytochemical and ultrastructural examinations of microglial cells in frontal lobe, mesencephalon and cerebellum were carried out. A quantitative evaluation of developing microglia was performed in comparison with astroglial cells by counting the mean number of cells per 1 mm2. The study indicated that microglial cells emerge at the same time in all structures under study, both in normal fetuses and in those with Down's syndrome. It was also found that ameboid microglia (AM) and ramified microglia (RM) emerge at the same time and show the same morphological structure in both groups of fetuses. It was revealed that in the CNS of fetuses with Down's syndrome, the number of ramified microglial cells increased significantly as compared with in normal fetuses. Astroglial cells outnumbered microglial cells in the normal fetal development. Due to the enhanced number of RM cells in the CNS of fetuses with Down's syndrome the quantitative difference between these cells obliterated, and microglial cells in the frontal lobe cortex even outnumbered astroglial cells.
该研究对72例妊娠8至22周（GW）的正常人类胎儿以及30例妊娠17至22周、经基因确诊为唐氏综合征的胎儿的中枢神经系统（CNS）组织进行。对额叶、中脑和小脑中的小胶质细胞进行了组织化学、免疫细胞化学和超微结构检查。通过计算每1平方毫米的平均细胞数，与星形胶质细胞相比，对发育中的小胶质细胞进行了定量评估。研究表明，在正常胎儿和唐氏综合征胎儿中，所有研究结构中的小胶质细胞同时出现。还发现，阿米巴样小胶质细胞（AM）和分支状小胶质细胞（RM）在两组胎儿中同时出现且形态结构相同。研究显示，与正常胎儿相比，唐氏综合征胎儿中枢神经系统中分支状小胶质细胞的数量显著增加。在正常胎儿发育过程中，星形胶质细胞的数量超过小胶质细胞。由于唐氏综合征胎儿中枢神经系统中RM细胞数量增加，这些细胞之间的数量差异消失，额叶皮质中的小胶质细胞甚至超过了星形胶质细胞。
