Hsiao K, Sachs G M, Schneider G E
J Neurosci. 1984 Feb;4(2):359-67. doi: 10.1523/JNEUROSCI.04-02-00359.1984.
Bilaterally projecting retinal ganglion cells (BPRGCs) in the adult Syrian golden hamster were identified through the use of two retrogradely transported neuronal labels, horseradish peroxidase and Nuclear Yellow, placed separately in each optic tract. The distribution and size of doubly labeled retinal ganglion cells were characterized and their numbers were determined. Strict criteria were used to exclude artifactual doubly labeled cells. This work revealed that: (a) BPRGCs comprise less than 0.01% of the entire retinal ganglion cell population, averaging 7.4 (SD = 3) cells per retina; (b) BPRGCs are found primarily in the upper, peripheral retina and not along the vertical meridian or in the temporal crescent; and (c) BPRGCs correspond in size to ordinary retinal ganglion cells in their immediate vicinity, thus providing no evidence that they comprise a separate population of cells. Electrophysiological collision experiments were also performed, with stimulating electrodes in the two brachia of the superior colliculi and a recording electrode in one optic nerve. A collision effect was not detected, thus supporting the anatomical findings of rare bilateral branching of optic nerve axons. The occurrence of BPRGCs may reflect occasional ambiguities in the cues that guide axons through the chiasm.
通过分别在每条视束中注入两种逆行运输的神经元标记物——辣根过氧化物酶和核黄，鉴定了成年叙利亚金黄地鼠双侧投射视网膜神经节细胞（BPRGCs）。对双重标记的视网膜神经节细胞的分布和大小进行了表征，并确定了它们的数量。使用严格的标准排除人为双重标记的细胞。这项研究表明：（a）BPRGCs占整个视网膜神经节细胞总数的比例不到0.01%，每个视网膜平均有7.4个（标准差=3）细胞；（b）BPRGCs主要位于视网膜上部周边区域，而非沿垂直子午线或颞侧新月区；（c）BPRGCs的大小与其紧邻的普通视网膜神经节细胞相当，因此没有证据表明它们构成一个独立的细胞群体。还进行了电生理碰撞实验，刺激电极置于上丘的两个臂中，记录电极置于一条视神经中。未检测到碰撞效应，从而支持了视神经轴突罕见双侧分支的解剖学发现。BPRGCs的出现可能反映了引导轴突穿过视交叉的线索中偶尔存在的模糊性。
