Gomes F L, Silveira L C L, Saito C A, Yamada E S
Departamento de Fisiologia, Universidade Federal do Pará, Belém, PA, Brasil.
Braz J Med Biol Res. 2005 Jun;38(6):915-24. doi: 10.1590/s0100-879x2005000600014. Epub 2005 Jun 1.
We performed a quantitative analysis of M and P cell mosaics of the common-marmoset retina. Ganglion cells were labeled retrogradely from optic nerve deposits of Biocytin. The labeling was visualized using horseradish peroxidase (HRP) histochemistry and 3-3'diaminobenzidine as chromogen. M and P cells were morphologically similar to those found in Old- and New-World primates. Measurements were performed on well-stained cells from 4 retinas of different animals. We analyzed separate mosaics for inner and outer M and P cells at increasing distances from the fovea (2.5-9 mm of eccentricity) to estimate cell density, proportion, and dendritic coverage. M cell density decreased towards the retinal periphery in all quadrants. M cell density was higher in the nasal quadrant than in other retinal regions at similar eccentricities, reaching about 740 cells/mm(2) at 2.5 mm of temporal eccentricity, and representing 8-14% of all ganglion cells. P cell density increased from peripheral to more central regions, reaching about 5540 cells/mm(2) at 2.5 mm of temporal eccentricity. P cells represented a smaller proportion of all ganglion cells in the nasal quadrant than in other quadrants, and their numbers increased towards central retinal regions. The M cell coverage factor ranged from 5 to 12 and the P cell coverage factor ranged from 1 to 3 in the nasal quadrant and from 5 to 12 in the other quadrants. These results show that central and peripheral retinal regions differ in terms of cell class proportions and dendritic coverage, and their properties do not result from simply scaling down cell density. Therefore, differences in functional properties between central and peripheral vision should take these distinct regional retinal characteristics into account.
我们对普通狨猴视网膜的M细胞和P细胞镶嵌结构进行了定量分析。通过将生物胞素注入视神经来逆行标记神经节细胞。使用辣根过氧化物酶（HRP）组织化学方法和3,3'-二氨基联苯胺作为显色剂来观察标记情况。M细胞和P细胞在形态上与在旧世界和新世界灵长类动物中发现的细胞相似。对来自不同动物的4个视网膜中染色良好的细胞进行了测量。我们分析了从中央凹（偏心度2.5 - 9毫米）起距离增加时，内层和外层M细胞及P细胞的单独镶嵌结构，以估计细胞密度、比例和树突覆盖范围。在所有象限中，M细胞密度均向视网膜周边降低。在相似偏心度下，鼻侧象限的M细胞密度高于视网膜其他区域，在颞侧偏心度2.5毫米处达到约740个细胞/平方毫米，占所有神经节细胞的8 - 14%。P细胞密度从周边向更中央区域增加，在颞侧偏心度2.5毫米处达到约5540个细胞/平方毫米。在鼻侧象限，P细胞占所有神经节细胞的比例低于其他象限，且其数量向视网膜中央区域增加。在鼻侧象限，M细胞覆盖因子范围为5至12，P细胞覆盖因子范围为1至3；在其他象限，P细胞覆盖因子范围为5至12。这些结果表明，视网膜中央和周边区域在细胞类别比例和树突覆盖方面存在差异，其特性并非简单地由细胞密度缩放所致。因此，中央视觉和周边视觉功能特性的差异应考虑到这些不同的视网膜区域特征。
