人胎端脑额叶代谢型谷氨酸受体5的发育性表达及细胞定位

Developmental expression and cellular distribution of metabotropic glutamate receptor 5 in the frontal cortex of human fetus

目的探讨人类胚胎期大脑额叶、脑室区（VZ）和脑室下区（SVZ）内代谢型谷氨酸受体5（mGluR5）的表达规律及细胞分布。方法将收集的引产胎儿按胎龄分为4组：9~11周,14~16周,22~24周和32~36周。切取额叶及含VZ、SVZ的脑组织固定后切片,免疫组织化学染色后观察额叶、VZ和SVZ内mGuR5的表达及其细胞定位。结果 9~36周的胚胎额叶及VZ、SVZ都有mGluR5表达,边缘带和皮质板内的免疫反应程度强于VZ和SVZ,阳性产物主要位于细胞膜。表达mGluR5的细胞主要为VZ和SVZ内的神经干/祖细胞、边缘带和VZ内的成熟前神经元及皮质板内的大量成熟神经元。结论人类胚胎额叶、VZ和SVZ内均有mGluR5表达,提示mGluR5可能参与了人类大脑皮质发生的调节过程。

Objective To investigate the expression of metabotropic glutamate receptor 5（mGluR5） and its cellular distribution in the frontal cortex,ventricular zone（VZ） and subventricular zone（SVZ） in human fetuses.Methods According to the gestational age,the collected fetuses were divided into 4 groups,namely 9-11 weeks,14-16 weeks,22-24 weeks and 32-36 weeks.Brain tissue blocks including the frontal lobe or VZ/SVZ were prepared into slices,and the expression pattern and cellular distribution of mGluR5 in the frontal cortex and VZ/SVZ were observed by immunohistochemistry or immunofluorescence.Results mGluR5 immunoreactivity was present in the cell membrane in the frontal cortex,VZ and SVZ from the 9th to 36th weeks and the immunoreactivity in the marginal zone（MZ） and cortical plate（CP） was markedly stronger than that in VZ and SVZ.The cells expressing mGluR5 included neural stem/progenitor cells in the VZ and SVZ,immature neurons in the VZ and MZ,and numerous mature neurons in the CP.Conclusion mGluR5 is expressed by a variety of cells such as neural stem cells in the frontal cortex,VZ and SVZ in human fetus,suggesting a role of mGluR5 in the development of human cerebral cortex.