P物质样免疫反应性神经元在蟾蜍视网膜的定位与分布

LOCALIZATION AND DISTRIBUTION OF SUBSTANE P-LIKE IMMUNOREACTIVE NEURONS IN THE TOAD RETINA

用免疫组织化学ＡＢＣ方法，研究Ｐ物质（ＳＰ）样免疫反应性神经元在蟾蜍视网膜的定位与分布。结果表明：在５８０个免疫反应阳性细胞中。４３％为Ⅰ型无长突细胞，４１％为Ⅱ型无长突细胞，１６％的细胞体位于节细胞层，暂定为移位无长突细胞。ＳＰ样免疫反应突起分布于内网层的第１、３、５亚层，以第３亚层最丛密，形成一致密的网层，第５亚层次之，第１亚层最稀少，不形成连续的网层。在视网膜平铺片上，ＳＰ样免疫反应细胞体均匀分布于视网膜中央区和周围区，其密度为５３６±１０７个／ｍｍ２（平均数±标准差）。它们的树突野呈对称和非对称两型，前者的树突野大小为５００～７００ｍ×２００～５００ｍ，后者的长突约为３００～５００ｍ。

The localization and distribution of substance P (SP)-1ike immunoreactive neurons in the toad retina were studied with immunohistochemistry ABC method. The result showed that of 580 SP-like immunoreactive neurons observed , 43% were Type Ⅰ amacrine cells , 41% of SP-positive cells were classified as Type Ⅱ amacrine cells , while 1 6% of SP-positive cells had their cell bodies located in ganglion cell layer (GCL ) and were designated as displaced amacrine cells. The SP-immunostaining processes formed a dense band in sublamina 3 of in- ner plexform layre(IPL) , spare immunopositive fibers could also be seen in sublamina 1 and 5 of the IPL. An examination of retinal whole mounts revealed that SP-immunoreactive neu- rons were distributed throughout the center and periphery of the retina. The density of SP- immunoreactive amacrine cells was calculated to be 536±107 cells per mm2 (x±s). The den- dritic fields of SP-immunoreactive amacrine cells were observed to be either symmetrically or asymmetrically distributed about their somas. The symmetrical dendritic fields ranged in di- ameter form 500～700m by 200～500m , and the processes forming asymmetrical dendritic fields ranged from 300～500m in length.