FUNCTIONAL ANATOMY OF THE SOMATOSENSORY CORTEX OF THE MONKEY

通过使用解剖学标记来追踪 躯体感觉皮层区域，我们已经确定了两种可能的 躯体感觉信息到达边缘系统的途径 对躯体感觉记忆很重要的结构 一条路线课程 背侧从中央后带通过后顶骨 通过扣带皮层进入边缘系统。 这一通路可能在功能上类似于枕顶神经通路 空间视觉的途径。 第二条路线向腹侧行进 从中央后带通过SII和岛叶皮质到 杏仁核，并通过鼻皮质间接到海马。 我们现在有强有力的证据表明，第二种途径是类似的 到枕颞部的视觉通路 一是通过 记录SII地区的单单位和多单位活动， 接受了rhe选定部分损伤的半球 后中心体表征，我们已经证明了 SII的相应表示，表明至少 腹侧定向躯体感觉通路的这一部分， 排列成皮层层级。 一个意想不到的发现， 研究表明，在中枢后病变后，SII区 经历了主要的功能重组，因为SII组织 被原代表空出的位置并没有保持沉默，而是， 相反，被不同身体的代表占据的卧室 部分，提供了以前未被承认的程度的证据， 成年灵长类的皮质可塑性。 我们的神经行为 有证据表明，双侧岛叶病变引起严重的 触觉识别缺陷，与以下建议一致， 岛叶皮层是顶叶-岛叶-边缘系统中关键环节 触觉识别的途径，因此占据了一个位置， 类似于枕-颞-边缘通路中的TE区 视觉识别。 这些比较表明，感官- 边缘系统通过等级组织的皮层相互作用 通路是所有感觉器官中记忆形成的共同机制。 方式。

By use ot anatomical markers-to trace the connections between somatosensory cortical fields, we have identified two possible routes by which somatosensory information could reach limbic structures important for somatosensory memory. One route courses dorsally from the postcentral strip through posterior parietal cortex and has access to the limbic system via cingulate cortex. This pathway may be functionally analogous to the occipitoparietal pathway for spatial vision. The second route courses ventrally from the postcentral strip through SII and insular cortex to the amygdala and indirectly to the hippocampus through rhinal cortex. We now have strong evidence that this second pathway is analogous to the occipitbtemporal pathway for object vision. First, by recording single- and multi-unit activity from the SII region in hemispheres that had received lesions of selected portions of rhe postcentral body representation, we have demonstrated loss of the corresponding representation from SII, indicating that at least this part of the ventrally directed somatosensory pathway is arranged as a cortical hierarchy. An unexpected finding in this study was that, following a postcentral lesion, the SII region undergoes major functional reorganization, in that the SII tissue vacated by the original representation does not remain silent but, instead, bedomes occupied by representations of different body parts, providing evidence for a previously unrecognized degree of cortical plasticity in adult primates. Our neurobehavioral evidence indicates that bilateral insular lesions cause a severe tactile recognition deficit, consistent with the suggestion that insular cortex is a critical link in a parieto-insulo-limbic pathway for tactile recognition, and so occupies a position analogous to that of area TE in the occipito-temporo-limbic pathway for visual recognition. These comparisions suggest that sensory- limbic interaction through a hierarchically organized cortical pathway is a mechanism common to memory formation in all sensory modalities.