目的:以PPE-GFP转基因小鼠为研究工具,观察绿色荧光蛋白(GFP)阳性的脑啡肽(ENK)能神经元与钙结合蛋白D28K(CB)、钙视网膜蛋白(CR)和小白蛋白(PV)等钙结合蛋白(CaBPs)成员在视网膜的分布及共存情况。方法:利用免疫组织化学和免疫荧光双标染色的方法。结果:GFP阳性的ENK能细胞主要分布在视网膜内核层内缘,少量分布在节细胞层。所有的GFP阳性细胞均与神经元标志物NSE共存,但不与星形胶质细胞标志物GFAP共存。GFP与CB、CR和PV均有部分共存,其中GFP/CB共存神经元占GFP阳性细胞的8.65%,占CB阳性细胞的5.84%;GFP/CR共存神经元占GFP阳性细胞的18.18%,占CR阳性细胞的14.28%,且共存细胞仅见于内核层;GFP/PV共存细胞占GFP阳性细胞的68.75%,占PV阳性细胞的91.67%,共存细胞主要位于内核层,少量见于节细胞层。结论:ENK能神经元在视网膜内具有板层特异性的分布特点和与钙结合蛋白成员有不同的共存模式,上述结果为深入研究小鼠视网膜ENK能神经元的功能意义提供了形态学依据。
Objective:The present study was designed to observe the distribution and coexistence of enkephalin(ENK)and part of calcium-binding proteins including calbindin D28K(CB),calretinin(CR)and parvalbumin(PV)in the retina of the PPE-GFP transgenic mouse.Methods:Immunohistochemistry and double immunofluorescence labeling methods were used.Results:GFP-positive cells were mainly distributed in the inner part of the inner nuclear layer(INL)and some of them were also located in the ganglion cell layer(GCL).None of the GFP-positive cells were GFAP-positive astrocytes,while all of the GFP immunoreactivities were NSE-positive.We observed the coexistence of GFP with CB,CR or PV.The proportion of GFP/CB double-labeled neurons accounted for 8.65% and 5.8% of total GFP-and CB-positive neurons respectively.GFP/CR double-labeled neurons accounted for 18.18% and 14.2% of total GFP-and CR-positive neurons respectively.GFP/CR double-labeled neurons were distributed in the INL.The proportion of GFP/PV double-labeled accounted for 68.75% and 91.67% of total GFP-and PV-positive neurons respectively.GFP/PV double-labeled neurons were primarily distributed in the INL and some were located in the GCL.Conclusion:The present results indicate the layer specific expression pattern of GFP-positive ENKergic neurons in the retina and also provided morphological evidence for further functional studies.