Arikuni T, Watanabe K, Kubota K
Department of Anatomy, Osaka University Medical School, Japan.
J Comp Neurol. 1988 Nov 1;277(1):21-40. doi: 10.1002/cne.902770103.
The corticocortical connections between the arcuate area (Walker's areas 8A and 45 or Brodmann's area 8) and the premotor and supplementary motor areas (Vogts' area 6) in the brain of the macaque monkey were studied microscopically with wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), which was injected into Brodmann's area 8 primarily to elucidate the projections of area 8 into area 6. In addition, in the same material, the pattern of connections between the arcuate area and area 46 of the prefrontal cortex was studied. On the basis of the findings of the present study, an anatomical cortical hierarchy for areas 8, 6, and 46 is discussed. Anterogradely labeled axon terminals and retrogradely labeled cells appeared in the premotor area, in the supplementary motor area, and in area 46 on the side of injection; sites containing labeled axon terminals also contained labeled cells. In other words, the examined connections were reciprocal. In the labeled areas, labeled terminals and cells coexisted, and most formed radial columns. However, no labeling of cells and terminals was seen in the motor area (Brodmann's area 4). After injection of WGA-HRP into area 8A, labeled terminals and cells appeared predominantly in the superior premotor area (a region of the premotor area above the arcuate spur, Vogt and Vogt's upper areas 6a alpha and 6a beta), forming one, two, or three bands of label in the anteroposterior direction, whereas labeling occurred to a lesser extent in the inferior premotor area (a region of the premotor area below the arcuate spur, Vogt and Vogt's areas 4c, lower 6a alpha and 6b). In contrast, injection of WGA-HRP into area 45 resulted in the predominant labeling of the inferior premotor area with scant labeling in the superior premotor area. In the premotor area, labeled terminals were distributed over the entire cortical depth, although few were found in the lower half of layer III, and labeled cells were distributed mainly in layer III. In area 46 of the banks of the principal sulcus in the prefrontal cortex, labeled terminals were distributed in all cortical layers or over the entire cortical depth with a lower concentration in layer IV; labeled cells were found mostly in layers III and V, with a relatively high density in layer V.
运用结合了小麦胚芽凝集素的辣根过氧化物酶（WGA-HRP），对猕猴大脑中弓形区（沃克氏8A区和45区或布罗德曼8区）与运动前区及辅助运动区（沃格茨6区）之间的皮质皮质连接进行了显微镜研究。将WGA-HRP注入布罗德曼8区，主要是为了阐明8区向6区的投射。此外，在相同材料中，还研究了弓形区与前额叶皮质46区之间的连接模式。基于本研究的结果，讨论了8区、6区和46区的解剖学皮质层级。顺行标记的轴突终末和逆行标记的细胞出现在注射侧的运动前区、辅助运动区和46区；含有标记轴突终末的部位也含有标记细胞。换句话说，所研究的连接是相互的。在标记区域，标记的终末和细胞共存，且大多数形成放射状柱。然而，在运动区（布罗德曼4区）未见细胞和终末的标记。将WGA-HRP注入8A区后，标记的终末和细胞主要出现在上运动前区（运动前区中弓形棘上方的区域，沃格茨和沃格茨的上6aα和6aβ区），在前后方向上形成一条、两条或三条标记带，而在下运动前区（运动前区中弓形棘下方的区域，沃格茨和沃格茨的4c区、下6aα和6b区）标记较少。相反，将WGA-HRP注入45区导致下运动前区标记为主，上运动前区标记较少。在运动前区，标记的终末分布于整个皮质深度，尽管在第III层下半部很少见，标记细胞主要分布在第III层。在额叶皮质主沟岸的46区，标记的终末分布于所有皮质层或整个皮质深度，在第IV层浓度较低；标记细胞大多见于第III层和第V层，在第V层密度相对较高。
