Landing B H, Shankle W R, Boyd J P
Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, California, USA.
Acta Paediatr Jpn. 1998 Oct;40(5):400-18. doi: 10.1111/j.1442-200x.1998.tb01959.x.
In this study, we searched for patterns in selected, quantitative microscopic features of the developing postnatal human cortex for 35 cytoarchitectural areas at eight age points from birth to 72 months. These data come from the largest extant survey of the microscopic features of the developing postnatal human cerebral cortex (JL Conel, 1939-67). In contrast to Jacobson's proposal that cortical surface area increases in proportion to brain weight, Conel's data show that surface area increases as brain weight2/3, with the maximal rate of increase in both brain weight and cortical surface area occurring from 1 to 3 months. We computed the numbers of cortical neurons per cortical layer under 1 mm2 of cortical surface (neurons/layer per mm2 column) and divided these values by the total neuron number/mm2 column. For all areas, these data show plateaux in most of the layers for periods of months to years, often preceded and followed by changes in their neuron number in a sinusoidal fashion. The age points of the maxima and minima of such laminar values differ across the 35 cortical areas, indicating that their sinusoids are phase-shifted with respect to each other. Ranking the six layers in each area at each age point by their neuron number/layer per mm2 column shows that, by 72 months, the first areas to receive thalamic auditory or visual input (primary sensory and unimodal association cortices) have the most neurons in layer 4 and in either layer 3 or 6. In contrast, by 72 months, other areas have the most neurons in layers 3 and 6, with the primary motor cortex reaching this ranking earlier than any other area. For temporal and parietal association areas, layers 2 (short cortico-cortical connections) and 4 (thalamo-cortical connections) have the most neurons from birth to 6 months, whereas layers 3 (long cortico-cortical connections) and 6 (cortico-thalamic connections) have the most neurons by 72 months. The quantitative, statistically non-random patterns demonstrated by our analyses suggest that hierarchical correlations between such structural changes and age-specific behavioral acquisitions exist during the first 72 months of postnatal development.
在本研究中，我们从出生到72个月的八个年龄点，对35个细胞构筑区域的产后发育中的人类皮质的选定定量微观特征进行了模式搜索。这些数据来自现存最大规模的产后发育中的人类大脑皮质微观特征调查（JL·科内尔，1939 - 1967年）。与雅各布森提出的皮质表面积与脑重量成比例增加的观点相反，科内尔的数据表明，表面积随脑重量的2/3增加，脑重量和皮质表面积的最大增加速率出现在1至3个月。我们计算了每平方毫米皮质表面下各皮质层的皮质神经元数量（每平方毫米柱体的神经元/层），并将这些值除以每平方毫米柱体的总神经元数量。对于所有区域，这些数据显示，在数月至数年的时间里，大多数层呈现出平稳期，其神经元数量通常以正弦方式在平稳期之前和之后发生变化。这种层状值的最大值和最小值的年龄点在35个皮质区域中各不相同，表明它们的正弦波相互之间存在相位偏移。在每个年龄点，按每平方毫米柱体的神经元数量/层对每个区域的六层进行排序，结果显示，到72个月时，最早接受丘脑听觉或视觉输入的区域（初级感觉和单峰联合皮质）在第4层以及第3层或第6层中神经元数量最多。相比之下，到72个月时，其他区域在第3层和第6层中神经元数量最多，初级运动皮质比其他任何区域更早达到这一排名。对于颞叶和顶叶联合区域，从出生到6个月，第2层（短皮质 - 皮质连接）和第4层（丘脑 - 皮质连接）神经元数量最多，而到72个月时，第3层（长皮质 - 皮质连接）和第6层（皮质 - 丘脑连接）神经元数量最多。我们分析所展示的定量、统计学上非随机的模式表明，在出生后发育的前72个月期间，这种结构变化与特定年龄行为习得之间存在层级相关性。
