Horton J C, Hocking D R
Beckman Vision Center, University of California, San Francisco 94143-0730, USA.
J Neurosci. 1996 Nov 15;16(22):7228-39. doi: 10.1523/JNEUROSCI.16-22-07228.1996.
Little is known about intrinsic variation from animal to animal in the periodicity of columnar systems within various regions of the mammalian cerebral cortex. To address this issue, complete mosaics of the ocular dominance columns were reconstructed from flat-mounts of the left and right striate cortex (V1) in six normal adult macaques (Macaca fascicularis). To identify the columns, we enucleated the right eye and subsequently processed striate cortex for cytochrome oxidase (CO) activity. Average column areas for the intact eye and the missing eye were nearly equal, confirming that monocular enucleation in adult macaques produces negligible column shrinkage. The contralateral eye's columns occupied more territory than the ipsilateral eye's columns, even in the central visual field representation (0 degree to 8 degrees), where they predominated by 52 to 48%. The column mosaics showed remarkable variation in periodicity. The number of column pairs along the V1/V2 border ranged from 101 sets in one monkey to 154 sets in another. Average column width along the V1/V2 border ranged between 670 and 395 microns, a nearly twofold difference. The widest columns were found in the foveal representation. This high degree of innate variability should be taken into account when considering the effects of various sensory manipulations (e.g., strabismus, anisometropia), which have been reported to alter the periodicity of ocular dominance columns. We found pronounced intrinsic variation in the width and number of ocular dominance columns in a sample of six M. fascicularis, indicating that the number of hypercolumns within a given cortical area can range widely among normal members of the same species.
关于哺乳动物大脑皮层不同区域柱状系统的周期性在不同动物个体间的内在差异，我们所知甚少。为解决这一问题，我们从六只正常成年猕猴（食蟹猴）左右纹状皮层（V1）的平铺标本中重建了完整的眼优势柱镶嵌图。为识别这些柱子，我们摘除了右眼，随后对纹状皮层进行细胞色素氧化酶（CO）活性处理。完整眼和缺失眼的平均柱面积几乎相等，这证实成年猕猴单眼摘除导致的柱收缩可忽略不计。对侧眼的柱所占区域比同侧眼的柱更多，即使在中央视野表征（0度至8度）中也是如此，在该区域对侧眼的柱占比为52%至48%。柱镶嵌图在周期性上表现出显著差异。沿V1/V2边界的柱对数量在一只猴子中为101组，在另一只猴子中为154组。沿V1/V2边界的平均柱宽在670至395微米之间，相差近两倍。最宽的柱出现在中央凹表征中。在考虑各种感觉操作（如斜视、屈光参差）的影响时，应考虑到这种高度的先天变异性，据报道这些操作会改变眼优势柱的周期性。我们在六只食蟹猴的样本中发现眼优势柱在宽度和数量上存在明显的内在差异，这表明在同一物种的正常个体中，给定皮层区域内超柱的数量可能有很大差异。
