Michael C R
Department of Cellular and Molecular Physiology, Yale Medical School, New Haven, CT 06510.
Proc Natl Acad Sci U S A. 1988 Jul;85(13):4914-8. doi: 10.1073/pnas.85.13.4914.
Optic tract fibers and cell bodies in the lateral geniculate nucleus of the monkey were studied intracellularly with micropipette electrodes containing the marker enzyme horseradish peroxidase. Single optic-tract fibers always projected to only one of the six geniculate layers. The majority of the axons innervating the four parvocellular laminae were red/green opponent color units; their terminations formed cylindrical columns that were perpendicular to the layers. In similar fashion, the geniculate cells in the parvocellular layers were mostly red/green units with narrow, bipolar dendritic fields oriented normal to the laminar borders. The majority of the retinal axons ending in parvocellular layers 6 and 5 were on-center units; nearly all geniculate cells in these two laminae were also on-center neurons. In layers 4 and 3 most terminating optic-tract fibers, as well as the geniculate cells themselves, were off-center units. All axons projecting to the magnocellular layers were broad-band units with spherical terminal arborizations. The magnocellular geniculate neurons, which were also broad band, had extensive spherical dendritic fields that often crossed laminar borders. Thus, the terminal patterns of each class of retinogeniculate axon closely resembled the dendritic orientations of the functionally related geniculate target cells.
用含有标记酶辣根过氧化物酶的微电极对猴子外侧膝状核中的视束纤维和细胞体进行了细胞内研究。单根视束纤维总是只投射到六个膝状层中的一层。支配四个小细胞层的大多数轴突是红/绿拮抗色单位；它们的终末形成垂直于各层的圆柱状柱体。同样，小细胞层中的膝状细胞大多是红/绿单位，其狭窄的双极树突野垂直于层界。终止于小细胞层6和5的大多数视网膜轴突是中心兴奋单位；这两层中几乎所有的膝状细胞也是中心兴奋神经元。在4层和3层中，大多数终止的视束纤维以及膝状细胞本身都是中心抑制单位。所有投射到大细胞层的轴突都是具有球形终末分支的宽带单位。大细胞膝状神经元也是宽带的，具有广泛的球形树突野，这些树突野常常跨越层界。因此，每一类视网膜-膝状体轴突的终末模式与功能相关的膝状靶细胞的树突方向密切相似。
