Beck P D, Kaas J H
Department of Psychology, Vanderbilt University, Nashville, TN 37240.
Brain Res. 1994 Jul 18;651(1-2):57-75. doi: 10.1016/0006-8993(94)90680-7.
Interhemispheric connections were studied by injecting a mixture of horseradish peroxidase (HRP) and wheatgerm agglutinin conjugated with horseradish peroxidase (WGA-HRP) into multiple sites in dorsolateral occipital and parietal cortex of one cerebral hemisphere of three galagos (Galago crassicaudatus) and two owl monkeys (Aotus trivirgatus) within seven days of birth. Cortex was either separated from the rest of the brain, flattened and cut parallel to the surface to aid reconstructing surface-view patterns of labeled neurons and processes, or cut in standard coronal or parasagittal planes to better reveal laminar patterns of connections. In both primate species, the surface-view pattern of callosal connections in infants was remarkably adult-like. In infant owl monkeys, callosal connections were concentrated along the margin of area 18 with area 17, and only a few labeled cells were found within area 17. Other visual areas including the second visual area, V-II, and the middle temporal visual area, MT, had patchy distributions of labeled neurons that extended over large parts of the visual field representations. Primary motor, auditory, and somatosensory fields also had patchy distributions of labeled neurons, with regions of areas 3b and adjoining somatosensory fields having few callosal connections in portions that appeared to correspond with representations of the hand and foot. Results were very similar in galagos, except that newborn galagos, as in adults, had a patchy distribution of callosally projecting neurons that extended well within area 17. Furthermore, the labeled neurons were concentrated in patches that aligned with the cytochrome oxidase blobs of area 17. Finally, callosal connections were concentrated in cytochrome oxidase poor regions of area 3b.
在三只粗尾婴猴（Galago crassicaudatus）和两只夜猴（Aotus trivirgatus）出生后七天内，将辣根过氧化物酶（HRP）和与辣根过氧化物酶结合的麦胚凝集素（WGA-HRP）的混合物注射到一个大脑半球的背外侧枕叶和顶叶皮质的多个部位，研究半球间连接。将皮质与大脑其余部分分离，展平并平行于表面切割，以帮助重建标记神经元和突起的表面视图模式，或者在标准冠状面或矢状面切割，以更好地揭示连接的层状模式。在这两种灵长类动物中，婴儿胼胝体连接的表面视图模式与成年动物非常相似。在婴儿夜猴中，胼胝体连接集中在18区与17区的边缘，在17区内仅发现少数标记细胞。其他视觉区域，包括第二视觉区V-II和颞中视觉区MT，有标记神经元的斑片状分布，延伸到视野表征的大部分区域。初级运动、听觉和躯体感觉区也有标记神经元的斑片状分布，3b区和相邻躯体感觉区的部分区域在似乎与手和脚的表征相对应的部分胼胝体连接很少。在婴猴中的结果非常相似，只是新生婴猴与成年猴一样，胼胝体投射神经元有斑片状分布，延伸到17区内。此外，标记神经元集中在与17区细胞色素氧化酶斑对齐的斑块中。最后，胼胝体连接集中在3b区细胞色素氧化酶缺乏的区域。
