兔视网膜中P物质样免疫反应神经元的发育

THE DEVELOPMENT OF SUBSTANCE P-LIKE IMMUNOREACTIVE NEURONS IN THE RABBIT RETINA

本实验用免疫细胞化学ABC法,研究了成年、新生和生后兔视网膜中P物质(SP)样免疫反应神经元的定位和发育。结果表明,成年兔视网膜SP样免疫反应细胞胞体位于内核层和节细胞层,胞突分布在内网层的第1、3、5亚层,偶见于视神经纤维层。细胞密度以视纹最高,从视纹向背腹视网膜边缘区密度渐变小。在新生兔视网膜已有SP阳性胞体和胞突出现,胞体主要位于节细胞层,突起在内网层第5亚层,但未形成连续网层,在第1亚层很少,第3亚层未见SP阳性突起。SP阳性细胞密度从新生到生后第4天增加,生后第6天到第12天细胞密度渐下降。生后第12天SP阳性胞体主要位于内核层。生后第20天,SP阳性细胞的形态、密度与分布已接近成年水平。上述结果提示,在兔视网膜中SP样免疫反应胞体和突起在生前已出现,生后继续发育,到生后20天后其形态发育已接近成熟。

The localization and development of substance P (SP) like immunoreactive retinal neurons in the adult, newborn and postnatal New Zealand albino rabbits were studied with immuaocytochemistry ABC method. We found most of the SPlike immunoreactive somas in adult rabbit retina located in inner margin of inner nuclear layer (INL) and ganglion cell layer (GCL). Their processes ramified in the lamina 1,3 and 5 of inner plexiform layer (IPL). Some immunoreaetive fibers in the layer of optic nerve fiber (LON) were occasionally observed. The highest cell density of SP-like somas occured in the visual streak (VS). The cell density gradually decreased from the VS to the ventral and dorsal periphery. In the new born rabbit retina, the labelled cell bodies and their processes appeared. Most of them located in the GCL, and a few of them located in the' INL. Their processes formed discontinuous layer in the lamina 5 and never seen in the lamina 3. The cell density of SP positive somas gradually increased from newborn to postnatal 4 th day. From postnatal 6 th day to 12 th day, the cell density gradually decreased. From postnatal 12 th day the somas mainly located in the INL. On the 20th day after birth the distribution and morphology of SP-like immunoreactive somas and processes had approached that of mature age. These results suggest that rabbit retinal SP-like immunoreactive neurons had appeared at prenatal period and continuously developed after birth.