目的探讨脑出血是否能促进大鼠海马齿状回神经再生。方法使用Western blotting、免疫组化染色和免疫荧光双标等方法并结合激光共聚焦显微镜技术对脑出血大鼠海马齿状回神经再生进行检测。结果与正常对照大鼠比较,同侧海马齿状回DCX蛋白在脑出血1 d即表达增强(0.127±0.088 vs 0.202±0.062),14 d达到高峰(0.771±0.108,P<0.01),28 d开始降低(0.582±0.121,P<0.01)。同时发现DCX和BrdU免疫阳性细胞以及DCX和BrdU免疫双标细胞出现在海马齿状回。与对照组相比,脑出血28 d大鼠海马齿状回颗粒细胞层BrdU和NeuN免疫双标细胞显著增加(1.808±1.020 vs 5.654±1.671,P<0.01)。结论脑出血能促进大鼠海马齿状回神经再生。
Objective Metabotropic glutamate receptor 5 （mGluR5） is concentrated in zones of active neurogenesis in the prenatal and postnatal rodent brain and plays an important role in the regulation of neurogenesis. However, little is known about mGluR5 in the prenatal human brain. Here, we aimed to explore the expression pattern and cellular distribution of mGluR5 in human fetal hippocampus. Methods Thirty-four human fetuses were divided into four groups according to gestational age： 9-11, 14-16, 22-24 and 32-36 weeks. The hippocampus was dissected out and prepared. The protein and mRNA expression of mGluR5 were evaluated by Western blot and immunohistochemistry or real-time PCR. The cellular distribution of mGluR5 was observed with double-labeling immunofluorescence. Results Both mGluR5 mRNA and protein were detected in the prenatal human hippocampus by real-time PCR and immunoblotting, and the expression levels increased gradually over time. The immunohistochemistry results were consistent with immunoblotting and showed that mGluR5 immunoreactivity was mainly present in the inner marginal zone （IMZ）, hippocampal plate （HP） and ventricular zone （VZ）. The double-labeling immunoftuorescence showed that mGluR5 was present in neural stem cells （nestin-positive）, neuroblasts （DCX-positive） and mature neurons （NeuN-positive）, but not in typical astrocytes （GFAP- positive）. The cells co-expressing mGluR5 and nestin were mainly located in the IMZ, HP and subplate at 11 weeks, all layers at 16 weeks, and CA 1 at 24 weeks. As development proceeded, the number of mGluR5/nestin double-positive cells decreased gradually so that there were only a handful of double-labeled cells at 32 weeks. However, mGluR5/DCX double-positive cells were only found in the HP, IZ and IMZ at 11 weeks. Conclusion The pattern ofmGluR5 expression by neural stern/progenitor cells, neuroblasts and neurons provides important anatomical evidence for the role of mGluR5 in the regulation of human hippocampal development.
