Deyoe E A, Hockfield S, Garren H, Van Essen D C
Department of Anatomy and Cellular Biology, Medical College of Wisconsin, Milwaukee 53226.
Vis Neurosci. 1990 Jul;5(1):67-81. doi: 10.1017/s0952523800000080.
We have examined the distribution of immunoreactivity for the monoclonal antibody Cat-301 in visual cortex of the macaque monkey. Remarkably, those portions of striate cortex (V1) and extrastriate cortex that are most immunoreactive for Cat-301 are anatomically interconnected and are dominated by inputs arising from the magnocellular layers of the LGN (which are themselves highly immunoreactive). In particular, we found that a band of Cat-301 labeled neurons known to exist in layer 4 of V1 is centered on the boundary between layers 4C alpha and 4B and thus includes portions of both the primary target of the magnocellular LGN and its subsequent relay through layer 4B. We also demonstrated consistently strong Cat-301 immunoreactivity in all three extrastriate targets of layer 4B: areas V3, MT, and the cytochrome-oxidase (CO) enriched thick stripes of V2. In V2, there was a close correlation between Cat-301 labeling and clusters of cells projecting to MT but not to V4. This was true even in regions where the CO pattern was equivocal or irregular, indicating that Cat-301 is a more reliable marker than CO for the thick-stripe subregions of V2. Finally, we found strong Cat-301 immunoreactivity in at least parts of areas V3A, the MST complex, and the posterior parietal complex, but not in area V4 or inferotemporal cortex. The molecular specificity revealed by this single marker thus correlates with functionally specific subdivisions at each hierarchical level over nearly the entire known extent of the visual pathway in macaques. This supports the notion that these subdivisions form an anatomically, physiologically, and now molecularly distinct pathway known as the M-stream.
我们研究了单克隆抗体Cat-301在猕猴视皮层中的免疫反应分布。值得注意的是，纹状皮层（V1）和纹外皮层中对Cat-301免疫反应最强的部分在解剖学上相互连接，并且主要由来自外侧膝状体大细胞层的输入所支配（外侧膝状体大细胞层本身就具有高度免疫反应性）。具体而言，我们发现V1第4层中已知存在的一条Cat-301标记神经元带以4Cα层和4B层之间的边界为中心，因此包括了大细胞外侧膝状体的主要靶区及其通过4B层的后续中继部分。我们还始终在4B层的所有三个纹外靶区中证明了强烈的Cat-301免疫反应：V3区、MT区以及V2区富含细胞色素氧化酶（CO）的粗条纹。在V2区，Cat-301标记与投射到MT区而非V4区的细胞簇之间存在密切相关性。即使在CO模式不明确或不规则的区域也是如此，这表明对于V2区的粗条纹亚区，Cat-301是比CO更可靠的标记物。最后，我们在V3A区、MST复合体和顶叶后复合体的至少部分区域中发现了强烈的Cat-301免疫反应，但在V4区或颞下皮层中未发现。因此，这一单一标记物所揭示的分子特异性与猕猴视觉通路几乎整个已知范围内每个层次水平上功能特异性的细分相关。这支持了这样一种观点，即这些细分形成了一条在解剖学、生理学以及现在在分子层面上都不同的通路，称为M流。
