Caminiti R, Zeger S, Johnson P B, Urbano A, Georgopoulos A P
J Comp Neurol. 1985 Nov 22;241(4):405-19. doi: 10.1002/cne.902410402.
The laminar and tangential distributions of association neurons projecting from areas 4 and 6 of the frontal lobe to area 5 of the superior parietal lobule were studied in macaque monkeys by using horseradish peroxidase histochemistry. In both areas 4 and 6 association neurons were medium-large pyramidal cells of layers II and III, and pyramidal and fusiform cells of layers V-VI. Tangentially, they were distributed unevenly over the cortical surface occupying only certain parts of areas 4 and 6, including the dorsomedial part of area 6, the proximal arm region of Woolsey's M1 map, parts of the postarcuate cortex, and the supplementary motor area. Within these projection zones, the number of projection cells waxed and waned in a periodic fashion. Quantitative methods, including spectral analysis techniques, were used to characterize precisely spatial periodicities along the rostrocaudal dimension. The same quantitative analyses were used to determine the nature of the tangential distribution of corticocallosal cells of area 5 projecting to contralateral area 5. Both association and callosal spectra contained a strong component in the range of low spatial frequencies, corresponding to periods greater than 2 mm. Moreover, a consistent peak was observed in both spectra at spatial frequencies corresponding to periods ranging from 0.85 to 1.28 mm. This peak is in accord with the hypothesis of a modular organization of the cells of origin of these projection systems.
运用辣根过氧化物酶组织化学方法，在猕猴中研究了从额叶4区和6区投射到顶上小叶5区的联合神经元的分层和切线分布。在4区和6区，联合神经元均为II层和III层的中等大小锥体细胞，以及V - VI层的锥体细胞和梭形细胞。从切线方向看，它们在皮质表面分布不均，仅占据4区和6区的特定部分，包括6区的背内侧部分、伍尔西M1图的近端臂区域、弓状后皮质的部分区域以及辅助运动区。在这些投射区内，投射细胞的数量呈周期性增减。采用包括频谱分析技术在内的定量方法，精确表征沿 rostrocaudal 维度的空间周期性。使用相同的定量分析来确定5区投射到对侧5区的胼胝体皮质细胞的切线分布性质。联合光谱和胼胝体光谱在低空间频率范围内都包含一个强成分，对应于大于2毫米的周期。此外，在对应于0.85至1.28毫米周期的空间频率处，两个光谱中均观察到一个一致的峰值。这个峰值符合这些投射系统起源细胞模块化组织的假设。
