Evidence for a rostral-to-caudal somatotopic organization in human primary somatosensory cortex with mirror-reversal in areas 3b and 1
Evidence for a rostral-to-caudal somatotopic organization in human primary somatosensory cortex with mirror-reversal in areas 3b and 1
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DOI：
10.1093/cercor/13.9.987
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发表时间：
2003-09-01
期刊：
影响因子：
3.7
通讯作者：
Villringer, A
中科院分区：
文献类型：
--
作者：
Blankenburg, F;Ruben, J;Villringer, A
内侧到外侧的躯体定位是人类初级躯体感觉皮质(SI)的一个公认的特征；然而，目前还不清楚是否也存在类似于非人类灵长类动物的从吻端到尾端的躯体定位排列。因此，在这项对8名健康人进行的功能磁共振成像(FMRI)研究中，对依次位于第三指和手掌上的五个限定皮肤区域进行了无害的电脉冲刺激。在对侧SI的3b区内，在组分析和6个单独的受试者中，可以看到连续的皮质代表部位按从嘴到尾的方式排列。指尖位于吻端最多，而手指近端和手掌远端位于更多的尾部位置。在区域1中，群体分析显示了类似的离散表征模式。然而，与3b区相比，指尖位于最尾部，而手指的更近端部分被发现在1区内被表示为吻部。因此，1区的表征模式就像3b区的镜像。与手指和远侧手掌的代表相比，近侧手掌位于中央后回更内侧的位置。
Medial-to-lateral somatotopy is a well-established feature of the human primary somatosensory cortex (SI); however, it is unknown whether, similarly to non-human primates, a rostral-to-caudal somatotopic arrangement exists as well. Therefore, in this functional magnetic resonance imaging (fMRI) study on eight healthy human subjects, five circumscribed skin areas sequentially located on the third finger and the palm of the hand were stimulated with innocuous electrical pulses. Within area 3b of contralateral SI, successive cortical representation sites ordered in a rostral-to-caudal fashion were seen in the group analysis and in six individual subjects. The fingertip was located most rostrally, whereas the proximal parts of the finger as well as the distal palm were represented at more caudal locations. Within area 1, the group analysis revealed a similar pattern of discrete representations. However, in contrast to area 3b, the fingertip was located most caudally, whereas the more proximal parts of the finger were found to be represented rostrally within area 1. Thus, the representation pattern of area 1 appeared as a 'mirror image' of that of area 3b. In comparison to the representations of the finger and the distal palm, the proximal palm was found to be represented at a more medial position of the postcentral gyrus.