Clark S A, Allard T, Jenkins W M, Merzenich M M
Coleman Laboratory, University of California, San Francisco 94143.
Nature. 1988 Mar 31;332(6163):444-5. doi: 10.1038/332444a0.
Receptive fields (RFs) obtained at specific cortical sites can be used to define a topographic map of the body surface in adult mammalian somatosensory cortex. This map is not static, and RFs at particular cortical sites can change in size and location throughout adult life. Conversely, the cortical loci at which a given skin surface is represented can shift hundreds of micrometres across the cortex in the koniocortical field, area 3b (refs 1-12). This plasticity suggests that RFs derive not from rigid anatomical connections, but by the selection of a subset of a large number of inputs. We have proposed that inputs are selected on the basis of temporal correlation 11-15. Here we test this idea by altering the correlation of inputs from two adjacent digits on the adult owl monkey hand by surgically connecting the skin surfaces of the two fingers (the formation of syndactyly). This manipulation increases the correlation of inputs from skin surfaces of adjacent fingers. The striking discontinuity between the zones of representation of adjacent digits on the somatosensory cortex disappeared. These results support the hypothesis that the topography of the body-surface map in the adult cortex is influenced by the temporal correlations of afferent inputs.
在成年哺乳动物体感皮层的特定皮层位点获得的感受野（RFs）可用于定义体表的地形图。这一图谱并非一成不变，在成年期，特定皮层位点的感受野在大小和位置上都会发生变化。相反，在颗粒状皮层区域3b（参考文献1 - 12），给定皮肤表面所对应的皮层位点可在整个皮层上移动数百微米。这种可塑性表明，感受野并非源于固定的解剖学连接，而是通过从大量输入中选择一个子集形成的。我们曾提出，输入是基于时间相关性进行选择的[11 - 15]。在此，我们通过手术连接成年枭猴手部相邻两个手指的皮肤表面（形成并指）来改变来自这两个相邻手指的输入相关性，从而验证这一观点。这种操作增加了来自相邻手指皮肤表面输入的相关性。体感皮层上相邻手指代表区之间显著的不连续性消失了。这些结果支持了这样一种假说：成年皮层中体表图谱的拓扑结构受传入输入的时间相关性影响。
