Britto L R, Keyser K T, Hamassaki D E, Karten H J
Department of Neurosciences, University of California, San Diego, La Jolla 92093.
J Comp Neurol. 1988 Mar 1;269(1):109-17. doi: 10.1002/cne.902690109.
In birds, displaced ganglion cells (DGCs) constitute the exclusive source of retinal input to the nucleus of the basal optic root (nBOR) of the accessory optic system. Tyrosine-hydroxylase (TH) immunoreactivity was examined in the pigeon retina after injections of rhodamine-labeled microspheres into the nBOR. A population of about 400 DGCs was observed in each case to exhibit both TH immunoreactivity and rhodamine bead fluorescence. This corresponded to about 10-15% of the total number of identified DGCs in each retina. Double-labeled cells were medium- to large-size (12 to 20 microns in the largest axis) and were always located at the border between the inner nuclear and the inner plexiform layers. Their dendrites could be followed horizontally in lamina 1 of the inner plexiform layer for up to 300 microns from the cell body. The distribution of double-labeled DGCs appeared to be mostly peripheral, matching the overall distribution of identified DGCs. Larger DGCs (21-28 microns) were never seen to contain TH immunoreactivity. Examination of brain sections revealed plexuses of thin varicose TH-positive axons in all subdivisions of the nBOR. Unilateral enucleation produced an almost complete elimination of TH immunoreactivity in the contralateral nucleus. Such results suggest the existence of a population of catecholaminergic DGCs projecting into the accessory optic system of the pigeon. They also support the emerging hypothesis concerning the neurotransmitter heterogeneity of ganglion cells in the vertebrate retina.
在鸟类中，移位神经节细胞（DGCs）是视网膜向附属视觉系统的基底视根核（nBOR）输入信息的唯一来源。将罗丹明标记的微球注入nBOR后，对鸽视网膜中的酪氨酸羟化酶（TH）免疫反应性进行了检测。在每种情况下，都观察到约400个DGCs群体同时表现出TH免疫反应性和罗丹明珠荧光。这相当于每个视网膜中已鉴定DGCs总数的约10 - 15%。双标记细胞为中等到大型（最大轴径为12至20微米），且总是位于内核层和内网状层之间的边界处。它们的树突可以在内网状层的第1层中从细胞体水平延伸达300微米。双标记DGCs的分布似乎大多位于周边，与已鉴定DGCs的总体分布相匹配。从未见过较大的DGCs（21 - 28微米）含有TH免疫反应性。对脑切片的检查显示，nBOR的所有亚区都有细的曲张TH阳性轴突丛。单侧眼球摘除导致对侧核中TH免疫反应性几乎完全消失。这些结果表明存在一群投射到鸽附属视觉系统的儿茶酚胺能DGCs。它们也支持了关于脊椎动物视网膜中神经节细胞神经递质异质性的新假说。
