Rhoades R W, Mooney R D, Fish S E
Brain Res. 1985 Jan;349(1-2):171-81. doi: 10.1016/0165-3806(85)90141-5.
Anterograde and retrograde tracing methods were used to compare the subcortical projections of area 17 in ZRDCT-an, anophthalmic mice with those of sighted C57BL mice. In both groups, area 17 projected to the dorsocaudal striatum, the reticular, lateral and lateral posterior nuclei, the dorsal and vental lateral geniculate nuclei, the zona incerta, the anterior and posterior pretectal nuclei, the stratum griseum superficiale of the superior colliculus and the dorsolateral pons. Occasional labeled fibers in both groups were also seen in the ventrobasal nucleus, but it was not clear whether or not any axons terminated in this region. The projections to the superior colliculus and dorsal lateral geniculate nucleus were analyzed in greater detail. In both normals and blind mice the striate corticotectal projection arose from cells in layer V and that to the geniculate from neurons in lamina VI. The topographic organizations of these projections in the two groups were indistinguishable. The striate corticotectal projection to the colliculus in the anophthalmic mice did appear to terminate more dorsally in the stratum griseum superficiale than that in sighted animals. These data demonstrate that a signal from the retina is not required for either the restriction of 'visual' cortical axons to their normal subcortical targets or the achievement of normal topography within those target nuclei.
采用顺行和逆行追踪方法，比较无眼小鼠ZRDCT-an中17区的皮质下投射与正常C57BL小鼠的皮质下投射。在两组中，17区均投射至背尾侧纹状体、网状核、外侧核和外侧后核、背侧和腹侧外侧膝状体核、未定带、前顶盖前核和后顶盖前核、上丘浅层和背外侧脑桥。两组中偶尔也可见到标记纤维出现在腹侧基底核，但不清楚是否有轴突终止于该区域。对投射至上丘和背外侧膝状体核的情况进行了更详细的分析。在正常小鼠和盲鼠中，纹状皮质到上丘的投射均起源于V层细胞，到外侧膝状体的投射起源于VI层神经元。两组中这些投射的拓扑组织没有区别。无眼小鼠中纹状皮质到上丘的投射似乎比正常小鼠的投射更终止于上丘浅层的背侧。这些数据表明，视网膜信号对于将“视觉”皮质轴突限制在其正常的皮质下靶点，或在这些靶核内实现正常的拓扑结构而言并非必需。
