一项研究发现，在从婴儿期到成年期扩张最多的人类大脑区域也是人类与其它灵长类动物分离的进化过程中扩张最多的区域。Jason Hill及其同事比较了12位新生儿和12位成年人的大脑扩张模式。尽管新生儿的大脑皮层的折叠和成年人一样复杂，它的总面积只有后者的1/3。这组科学家证明了尽管每个皮层区域都在扩张，包括顶叶、颞叶和前额叶皮层在内的一些区域的扩张几乎是岛皮层和中枕叶皮层等区域的两倍。这组作者把这些结果与人类和猕猴大脑皮层的差异进行了比较，作为比较人类大脑在进化过程中如何相对于祖先灵长类扩张的一种替代方式。这组作者发现，新生儿成熟过程中观察到的大脑扩张模式非常类似于成年人类与猕猴的大脑扩张的差异。此外，在婴儿期之后扩张较少的人类大脑区域倾向于在功能上更成熟，而且在成年期比扩张更多的区域的细胞结构更简单。这组科学家说，这些结果提示，让在新近的进化过程中扩张的区域在出生时不那么成熟可能具有益处。
论文 #10-01229: "Similar patterns of cortical expansion during human development and evolution," 作者 Jason Hill, Terrie Inder, Jeffrey Neil, Donna Dierker, John Harwell和 David Van Essen
媒体联系人：Jason Hill，圣路易斯华盛顿大学医学院解剖学和神经生物学系
Department of Anatomy and Neurobiology, Washington University in St. Louis School of Medicine, St. Louis, MO
电话：301-938-8713
电子邮件：hillj@wustl.edu
Published online before print July 12, 2010, doi: 10.1073/pnas.1001229107
Similar patterns of cortical expansion during human development and evolution
Jason Hilla,1, Terrie Indera, Jeffrey Neila, Donna Dierkerb, John Harwellb, and David Van Essenb
Abstract
The cerebral cortex of the human infant at term is complexly folded in a similar fashion to adult cortex but has only one third the total surface area. By comparing 12 healthy infants born at term with 12 healthy young adults, we demonstrate that postnatal cortical expansion is strikingly nonuniform: regions of lateral temporal, parietal, and frontal cortex expand nearly twice as much as other regions in the insular and medial occipital cortex. This differential postnatal expansion may reflect regional differences in the maturity of dendritic and synaptic architecture at birth and/or in the complexity of dendritic and synaptic architecture in adults. This expression may also be associated with differential sensitivity of cortical circuits to childhood experience and insults. By comparing human and macaque monkey cerebral cortex, we infer that the pattern of human evolutionary expansion is remarkably similar to the pattern of human postnatal expansion. To account for this correspondence, we hypothesize that it is beneficial for regions of recent evolutionary expansion to remain less mature at birth, perhaps to increase the influence of postnatal experience on the development of these regions or to focus prenatal resources on regions most important for early survival.
