摘要目的:探究γ-氨基丁酸(GABA)能视网膜神经节细胞的中枢投射区域以及投射到上丘的GABA能视网膜神经节细胞在视网膜中的分布情况及其形态特点。方法:取6只GABA转运蛋白(vGAT)-cre转基因小鼠(实验1组)及6只野生型C57BL/6小鼠(对照1组)，于双侧眼内玻璃体腔注射腺相关病毒rAAV-EF1α-DIO-EGFP-EGFP；取6只vGAT-cre转基因小鼠(实验2组)及6只野生型C57BL/6小鼠(对照2组)，于脑内双侧上丘注射腺相关病毒rAAV-EF1α-DIO-EGFP-EGFP。注射病毒后42 d时，取6只实验1组、6只对照1组及3只实验2组、3只对照2组小鼠的视网膜、视神经、脑组织，行冰冻切片的免疫荧光双标染色以检测绿色荧光蛋白(GFP)和GABA的表达；对3只实验2组、3只对照2组小鼠的全视网膜铺片行免疫荧光双标染色以检测GFP和转录因子Brn3蛋白(BRN3A)的表达并统计阳性细胞数、细胞胞体大小。结果:实验1组小鼠的视网膜内核层、内网状层、神经节细胞层均可见到表达GFP的绿色荧光信号和表达GABA的红色荧光信号共标，视神经中可见表达GFP的绿色荧光信号沿轴突纤维呈线样排列，外侧膝状体和上丘区域的脑组织中也可见到表达GFP的绿色荧光信号；而对照1组小鼠视网膜上无绿色荧光信号。实验2组小鼠的视网膜上表达GFP的绿色荧光信号与表达GABA的红色荧光信号存在共标，投射至上丘的GABA能视网膜神经节细胞以中小型细胞(直径12~16 μm)为主，其数量占细胞总数的(37.70±5.33)%，占所有神经节细胞(BRN3A阳性)的(7.27±0.81)%。结论:GABA能视网膜神经节细胞向脑内外侧膝状体及上丘区域投射，在视网膜上呈均匀分布且以中小型细胞为主。

abstractsObjective:To observe the central projection of GABAergic retinal ganglion cells (RGCs) and the distribution and morphology of GABAergic RGCs projected to the superior colliculus (SC) in retina.Methods:Six vesicular GABA transporter ( vGAT)- cre transgenic mice (experimental group I) and 6 wide-type C57BL/6 mice (control group I) were given injection of adeno-associated virus rAAV-EF1α-DIO-EGFP-EGFP into the bilateral vitreous chamber; 6 vGAT-cre transgenic mice (experimental group II) and 6 wide type C57BL/6 mice (control group II) accepted injection of adeno-associated virus rAAV-EF1α-DIO-EGFP-EGFP into the bilateral SC using stereotactic technique. Forty-two d after virus injection, 6 mice in the experimental group I, 6 mice in the control group I, 3 mice in the experimental group II, and 3 mice in the control group II were chosen; their retina, optic nerves and brain tissues were cut into slices for double-labelling immunofluorescent staining to detect the green fluorescent protein (GFP) and GABA expressions. Three mice in the experimental group II and 3 mice in the control group II were chosen to prepare stretched preparations of retina; they were performed double-labelling immunofluorescent staining to detect the GFP and BRN3A expressions, count the number of positive cells, and measure the cell body size. Results:In the experimental group I, the green fluorescence signal expressing GFP and red fluorescence signal expressing GABA were co-standardized in the inner plexiform layer, inner nuclear layer and ganglion cell layer of the retina, the green fluorescent signal expressing GFP could be observed in the optic nerves in a linear arrangement along the axon fibers, and green fluorescent signal expressing GFP was observed in the dorsal lateral geniculate nucleus and the superficial SC; while there was no green fluorescent signal in the retina of control group I. In the experimental group II, the green fluorescence signal expressing GFP and red fluorescence signal expressing GABA were co-standardized; the GABAergic RGCs projected to the SC were mainly small/medium-sized cells (diameter 12-16 μm), which was about (37.70±5.33)% of the total cell number and was about (7.27±0.81)% of the ganglion cells (with positive BRN3A).Conclusion:GABAergic RGCs projected to the dorsal lateral geniculate nucleus and SC are specified, and they are small/medium-sized cells and uniformly distributed in the retina.