【作者】 马云飞；

【导师】 陈耀星；

【作者基本信息】 中国农业大学 ， 基础兽医学， 2004， 硕士

【摘要】 本研究采用Nissl染色法、视神经溃变试验和神经元逆行追踪标记辣根过氧化物酶(HRP)和标记荧光追踪染料DiI的技术，分析比较了不同日龄北京鸭视网膜节细胞层细胞的大小、形态类型、数量与密度及其分布的变化，为阐明水禽——北京鸭的视觉特征及其形成机理积累形态学资料。研究结果如下： 1．视网膜节细胞层细胞形态多样，呈圆形、椭圆形和多角形等，由视网膜中央区至周边部随细胞大小递增(P8：1.7～3.0倍)而细胞密度梯度呈递减(P8：36％～47％)的变化，这种变化在颞侧周边部最明显，背侧周边部次之。随日龄增长，节细胞层细胞总数(P30／P0=1.4)和细胞大小(P30／P0=1.3)均递增而细胞平均密度递减(P30／P0=0.9)。 2．RGCs在视网膜中央有一个高密度区(P0：8 860个／mm~2：P8：7 600个／mm~2)，细胞大小由视网膜中央区至周边部递增(P8：1.1～2.2倍)而密度递减(P8：42％～49％)，这种变化趋势在颞侧周边部最明显，并且伴随日龄增长，RGCs总数和平均密度均递减(P0：1.3×10~6个，5 370个／mm~2：P8：1.26×10~6个，4 620个／mm~2)而细胞大小递增，由62.16±23.28μm~2(P0)增至69.94±35.95／μm~2(P8)(CA)或133.74±75.65μm~2(P0)增至152.87±55.86μm~2(P8)(TP)。 3．根据细胞体和树突野大小及树突分支特点，北京鸭RGCs被分为4型和6亚型，即小细胞体(81.25±24.51μm~2)和小树突野(14 446±8 702μm~2)的Ⅰ型，包括简单型Ⅰs亚型和复杂型的Ⅰc亚型；中等细胞体(201.17±65.99μm~2)和树突野(60 167±16 896μm~2)的Ⅱ型，也包括Ⅱs和Ⅱc两个亚型；中等细胞体(251.674±90.05μm~2)和大树突野(156 329±43 693μm~2)的Ⅲ型细胞，只有简单的Ⅲs亚型；大细胞体(471.20±72.31μm~2)和大树突野(189 320±42 438μm~2)的Ⅳ型细胞，只有复杂的Ⅳc亚型。各亚型比例分别是：Ⅰs亚型(28％)、Ⅰc亚型(32％)、Ⅱs亚型(14％)、Ⅱc亚型(8％)、Ⅲs亚型(13％)、Ⅳc亚型(5％)。各亚型RGCs在视网膜中央区和周边部出现的频率不同，中央区以小型细胞为主(77.2％)，大型树突野细胞仅占10.5％；而在颞侧周边部大树突野的Ⅲs亚型细胞比例明显增多(占25.4％)。 4．移位性无长突细胞(dACs)是位于视网膜节细胞层的小神经元，核深染，胞质很少，细胞体呈圆形或卵圆形，细胞大小均一，平均面积为23.65±3.97μm~2。dACs总数为0.64×10~6个，约占节细胞层细胞总数的17～30％，平均密度为1 720个／mm~2，在视网膜中央有一个dACs高密度区即中央高密度区(CA，约为3 860个／mm~2)，且dACs的密度由视网膜中央区向视网膜周边部逐渐降低(TP，约为1 780个／mm~2；NP，约为1 360个／mm~2)。更多还原

【Abstract】 The morphological type, size, number and density of cells in the ganglion cell layer (GCL) were studied by Nissl-staining, retrograde cell degeneration with axotomy of the optic nerve, retrograde cell labeling of horseradish peroxidase (HRP) and carbocyanine dye (OiI) in the retina of Beijing duck (P1, P8 and P30). It will supply important foundation for elucidating the visual characteristic and special visual mechanism of the waterfowl-Beijing duck. The results were demonstrated as follows:1. The cells in the ganglion cell layer (GCL) were round, oval and polygon in somata. From the central retina to the peripheral zone, the cell size increased as large as 1.7-3.0 times (P8), but the cell density decreased to 36%~47% (P8). The center-peripheral graduation was significant in TP. The total number of cells (P30/P0=1.4) and their sizes (P30/P0=1.3) increased with age, but the cell density on average decreased (P30/P0=0.9).2. One high-density area of the RGCs was observed in the central retina(CA)(P0:8 860 cells/mm2; P8: 7 600 cells/mm2). From the central retina to the peripheral zone, the size of RGCs increased as large as 1.1 ~ 2.2 times (P8), but the cell density decreased to 42%~49% (P8). The center-peripheral graduation was significant in TP. The total number and average density of RGCs (P0:1.3\×106 cells, 5 370 cells/mm2; P8: 1.26×106 cells, 4 620 cells/mm2) decreased with age, but the size of cells increased from P0 (62.16 ±23.28 um2 in CA, 133.74±75.65 um2 in TP) to P8 (69.94±35.95 um2 in CA, 152.87±55.86 um2 in TP).3. According to all sizes of somal area and dentritic field and dentritic branching pattern, the RGCs of Beijing duck were classified into 4 types and 6 subtypes. Type I cells had small somal area (81.25±24.51um2) and dentritic field (14 446±8 702 um2). They were further subdivided into 2 subtypes of Is and Ic. Type II cells had medium-sized soma (201.17±65.99 um2) and dentritic field (60 167±16 896 um2), and contained 2 subtypes of IIs and IIc. Type III cells had medium-sized soma (251.67±90.05um2) and large dentritic field (156 329±43 693 um2), and only contained a subtype of IIIs.Type IV cells had large soma (471.20±72.31 um2) and dentritic field (189 320±42 438 um2), and only contained a subtype of IVc. The proportion of each subtype was28% (Is), 32% (Ic), 14% (IIs), 8% (IIc),13% (IIIs), 5% (IVc). In the central retina (CA), the proportion of small type RGCs was 77.2%, but the large dentritic field RGCs only 10.5% in the temporal periphery (TP). The large dentritic field RGCs (subtype IIIs) were much more than in the central retina of Beijing duck (about 25.4%).4. The dACs of Beijing duck were found in the ganglion cell layer of retina, which had round or oval somata and their somata were small (23.65±3.97 um2 on average). Their karyon were stained homogeneously by cresyl violet. The total number of these cells was 0.64×106 cells and accounted for 17~30% of total cells in GCL. The cell density was 1 720 cells/mm2 on average. However, one high-density area was observed in the central retina (CA, 3 860 cells/mm2). The cell densities in the temporal periphery (TP) and the nasal periphery (NP) were 1 780 cells/mm2 and 1 360 cells/mm2. These results indicated that the size of dACs was no significant difference in the centrality and periphery, but a center-peripheral graduation was detected in the cell density.更多还原