Wall J T, Symonds L L, Kaas J H
J Comp Neurol. 1982 Oct 20;211(2):193-214. doi: 10.1002/cne.902110208.
Projections of the middle temporal visual area, MT, and of visual cortex adjoining MT were investigated with autoradiographic methods in the prosimian primate, Galago senegalensis. Ipsilateral cortical targets of MT included area 17, area 18, cortex caudal to MT, cortex ventral to MT, and parietal-occipital cortex dorsal to MT. This pattern of projections suggests that extrastriate cortex contains a number of visual subdivisions in addition to MT. Contralateral projections were to MT and parietal-occipital cortex. Projections from MT to areas 17 and 18 connected regions representing similar parts of the visual hemifield while the location of callosal projections in MT matched the location of the injection site in the other hemisphere. Label in area 17 was concentrated in layers I, III, and VI whereas other cortical areas were most densely labeled in the granular and supragranular layers. Subcortical projections of MT included the reticular nucleus of the thalamus, the lateral posterior nucleus, the superior pulvinar, the inferior pulvinar, the superior colliculus, and the pontine nuclei. The projection pattern to the superior and inferior pulvinar nuclei suggests that MT projects in a topographic manner to two subdivisions within each of these structures. Injections in cortex just outside of MT labeled area 18, inferotemporal cortex, parietal-occipital cortex, and, to a lesser extent, MT. The projections to inferotemporal cortex clearly distinguish the bordering cortex from MT. Contralateral cortical terminations were in locations corresponding to the injection site. Subcortical targets were generally similar to those seen after MT injections, although additional projections were observed depending on the location of the injection. Comparison of these results from the prosimian galago with studies in New and Old World monkeys indicates there are substantial similarities in projections. Thus, some of the cortical and thalamic subdivisions described for monkeys appear to exist in prosimians.
采用放射自显影方法，在原猴亚目灵长类动物 Senegal 婴猴中，对颞中视觉区（MT）以及与 MT 相邻的视觉皮层的投射进行了研究。MT 的同侧皮层靶点包括 17 区、18 区、MT 尾侧的皮层、MT 腹侧的皮层以及 MT 背侧的顶枕皮层。这种投射模式表明，除了 MT 之外，纹外皮层还包含多个视觉亚区。对侧投射至 MT 和顶枕皮层。从 MT 到 17 区和 18 区的投射连接了代表视觉半视野相似部分的区域，而胼胝体投射在 MT 中的位置与另一半球注射部位的位置相匹配。17 区的标记集中在 I、III 和 VI 层，而其他皮层区域在颗粒层和颗粒上层标记最为密集。MT 的皮层下投射包括丘脑网状核、外侧后核、上丘脑、下丘脑、上丘和脑桥核。对上丘脑和下丘脑核的投射模式表明，MT 以拓扑方式投射到这些结构中每个结构的两个亚区。在 MT 外侧的皮层进行注射，标记了 18 区、颞下皮层、顶枕皮层，在较小程度上也标记了 MT。对颞下皮层的投射清楚地将相邻皮层与 MT 区分开来。对侧皮层终末位于与注射部位相对应的位置。皮层下靶点通常与 MT 注射后所见的相似，尽管根据注射位置观察到了额外的投射。将原猴婴猴的这些结果与新旧世界猴的研究进行比较表明，投射存在实质性相似性。因此，为猴子描述的一些皮层和丘脑亚区似乎在原猴中也存在。
