人胎小脑内Calbind in和Parvalbum in的免疫组织化学研究(英文)

CALBINDIN AND PARVALBUMIN IN CEREBELLUM OF HUMAN FETUS

既往研究显示的哺乳动物小脑单位和小脑缝隙，在人类称之为Ｐｕｒｋｉｎｊｅ 细胞群和缝隙。进一步的研究证实，一种钙结合蛋白Ｃａｌｂｉｎｄｉｎ（ＣＢ）在啮齿动物小脑的发育过程中可作为Ｐｕｒｋｉｎｊｅ 细胞群的短时标志物。为了观察人胎Ｐｕｒｋｉｎｊｅ 细胞群和小脑缝隙的发育变化，并试图证实在小脑Ｐｕｒｋｉｎｊｅ 细胞的发育过程中钙结合蛋白的表达是否有差别，本文选用胎龄１３、１５、２０、２６、３２和３９ 周的小脑分别作ＣＢ和Ｐａｒｖａｌｂｕｍ ｉｎ（ＰＶ）的免疫组织化学反应，ＣＢ和ＰＶ 均显示内外方向的空间分布顺序，并且除１３ 周ＣＢ有表达而ＰＶ 没有表达外，其它胎龄均显示了相似的分布模式。在第１３ 周，ＣＢ阳性的Ｐｕｒｋｉｎｊｅ 细胞前体仅见于小脑蚓，而小脑半球则不存在，阳性细胞体和轴突组合成前后方向的细胞群，与非免疫反应性的条带交替出现。至第１５ 周，小脑蚓和半球的Ｐｕｒｋｉｎｊｅ 细胞均可被ＣＢ和ＰＶ 标记。ＣＢ和ＰＶ 阳性胞体和轴突以非免疫反应的缝隙为界，在小脑蚓和蚓旁组织组成纵向的细胞群。小脑叶片内Ｐｕｒｋｉｎｊｅ 细胞群和缝隙在前后和背腹方向上排列一致。小脑半球内的Ｐｕｒｋｉｎｊｅ 细胞缺乏这种条带状结构。从２４周起。

Previous studies demomstrated cereballar modules and raphes in mammals, which are named as Purkinje cell parcellation and the raphes in the human. Further, a calcium binding protein, calbindin(CB), was found to be a transient modular marker for Purkinje cells during development in the rodent cerebellum. The present study was to determine the developmental changes of Purkinie cell parcellation and the cerebellar raphes in human, and to verify if calcium binding proteins are expressed differentially in developing human Purkinje cells. The immunoreactivity of CB and PV was examined in the cerebella of human fetuses aged 13, 15, 20, 26, 32 and 39 weeks of gestation (W). CB and PV were expressed in a mediolateral spatial sequence, and exhibited similar distribution pattern at all ages except 13W when CB was present, but PV not. At 13W, CB reactive Purkinje cell precursors were found in the vermis but not the hemispheres. Positive cells and their axonal processes were organised in parasagittal compartments alternating with immunonegative strips, the raphes. By 15W, Purkinje cells in both the vermis and hemispheres were labelled by both CB and PV.CB and PV positive somata and axons in the vermis and paravermal regions were organised in distinct longitudinal compartments bordered by immunoreactivitv free raphes. The compartments and raphes were congruent within the folia in anteroposterior and dorsoventral directions. The hemispheric Purkinje cells lacked such a zonal organization. From 24 W to term, Purkinje cell compartments and the raphes both became more numerous, and increasingly irregular in size and orientation with age, and their longitudinal congruence across folia was largely lost by term. These findings indicate that human cerebellar Purkinje cells do not differentially express CB and PV at early developmental stage. However, the migration of Purkinje cell precursors and the growth of their axons result in the parcellation of cell bodies and axons and the formation of cerebellar raphes, both of which exhibit remarkable spatial and numeric changes during prenatal development.