Sur M, Nelson R J, Kaas J H
J Comp Neurol. 1982 Oct 20;211(2):177-92. doi: 10.1002/cne.902110207.
Microelectrode multiunit mapping techniques were used to determine the somatotopic organization of postcentral parietal cortex in the squirrel monkey Saimiri sciurus. Recordings were largeLy confined to architectonic areas 3b and 1. Results were compared to those from similar studies of owl (Merzenich et al., '78) and macaque (Nelson et al., '80) monkeys. As in these previous investigations, separate representations of the body surface were found in areas 3b and 1 of squirrel monkeys. These representations were organized in parallel, so that both proceeded from the tail on the medial wall of the cerebral hemisphere, to the lips and oral cavity on the lateral margin of these areas along the sylvian fissure. The representations were also roughly mirror images of each other so that whatever skin surface was represented rostrally in area 3b was represented caudally in area 1, and similar skin surfaces were represented along the common border. However, the representations were not identical. For example, the split representations of the leg differed so that the distal leg was represented in cortex lateral to that devoted to the foot in area 1 and medial to the foot in area 3b. Remarkably, the representations of some body parts were reversed in orientation in both area 3b and area 1 in squirrel monkeys as compared to owl and macaque monkeys. The face, arm, trunk, and leg representations were all reversed in squirrel monkeys, while the orientations of the hand and foot representations were the same. For example, the dorsal trunk is trunk is represented at the 3b/1 border in owl and macaque in area the ventral trunk is represented at th 3b/1 border in squirrel monkeys. These reversals of somatotopic organization in part but not all of the representations in areas 3b and 1 suggest that both fields are divided into sectors where the basic somatotopic orientation is independently determined, that the orientation of some of these sectors is subject to reversal in evolution, and that matching sectors in areas 3b and 1 are not independent in somatotopic organization.
采用微电极多单位记录技术来确定松鼠猴（Saimiri sciurus）中央后顶叶皮质的躯体定位组织。记录主要局限于结构分区3b和1区。将结果与对鸮猴（Merzenich等人，1978年）和猕猴（Nelson等人，1980年）的类似研究结果进行比较。与这些先前的研究一样，在松鼠猴的3b区和1区发现了体表的独立表征。这些表征是平行排列的，因此两者都从大脑半球内侧壁的尾部开始，沿着外侧裂到达这些区域外侧边缘的嘴唇和口腔。这些表征也大致互为镜像，所以在3b区靠前代表的任何皮肤表面在1区靠后代表，并且相似的皮肤表面沿着共同边界被代表。然而，这些表征并不完全相同。例如，腿部的分开表征有所不同，以至于小腿在1区中代表足部的皮质外侧、在3b区中代表足部的皮质内侧被代表。值得注意的是，与鸮猴和猕猴相比，松鼠猴3b区和1区中某些身体部位的表征在方向上是相反的。松鼠猴的面部、手臂、躯干和腿部表征全部颠倒，而手部和足部表征的方向相同。例如，在鸮猴和猕猴中，背侧躯干在3b/1边界处代表，而在松鼠猴中，腹侧躯干在3b/1边界处代表。3b区和1区部分而非全部表征中躯体定位组织的这些颠倒表明，这两个区域都被划分为基本躯体定位方向独立确定的扇区，这些扇区中的一些方向在进化过程中会发生颠倒，并且3b区和1区中匹配的扇区在躯体定位组织中并非独立。
