Pearson R C, Powell T P
Brain Res. 1985 Apr;356(1):89-107. doi: 10.1016/0165-0173(85)90020-7.
The projection of the cortex of the primary somatic sensory area (S1) upon area 5 in the rhesus monkey has been studied with axonal degeneration methods. There is little or no overlap between the major topographic representations in area 5 but there is both convergence and divergence within a representation; the degeneration after a small lesion in a representation in SI virtually fills the representation in area 5 and there is extensive overlap of the degeneration after two lesions in widely separated parts of the representation in S1. The representation of the arm in area 5 is surprisingly large, that of the face is relatively smaller than in S1 and the trunk and leg are about the same as in S1. Lesions in the trunk and face representations result in terminal degeneration throughout the antero-posterior extent of area 5, but after damage of the limb representations the degeneration in area 5 is concentrated into 3 medio-laterally disposed bands. Of the cytoarchitectonic subdivisions of S1, area 2 projects most heavily upon area 5 and area 3b the least, and there is a reversal in the antero-posterior dimension with more posterior parts of S1 projecting to more anterior parts of area 5. The corticocortical fibres from S1 end in layers III and IV of area 5, and while the degeneration in layer IV is continuous it is in distinct 'prongs' in layer III.
采用轴突退变方法对恒河猴初级躯体感觉区（S1）皮质在5区的投射进行了研究。5区主要的地形图表示之间几乎没有或没有重叠，但在一个表示内既有会聚又有发散；S1中一个表示内的小损伤后的退变几乎填满了5区的表示，并且在S1表示的广泛分离部分的两个损伤后的退变有广泛的重叠。5区中手臂的表示出奇地大，面部的表示相对小于S1中的表示，而躯干和腿部的表示与S1中的大致相同。躯干和面部表示中的损伤导致5区前后范围的终末退变，但肢体表示受损后，5区的退变集中在3个沿中-外侧排列的带中。在S1的细胞构筑亚区中，2区对5区的投射最重，3b区最轻，并且在前后维度上存在反转，S1的更后部投射到5区的更前部。来自S1的皮质皮质纤维终止于5区的III层和IV层，虽然IV层的退变是连续的，但在III层中呈明显的“叉状”。
