FUNCTIONAL ANATOMY OF THE SOMATOSENSORY CORTEX OF MONKEYS

在一系列的解剖实验中，我们已经确定了两条路线， 躯体感觉信息到达边缘结构， 躯体记忆 其中一条路线从中央邮政区的背面 通过后顶叶皮层进入边缘系统 扣带皮层 该途径可能在功能上类似于 空间视觉的枕顶通路。 第二路线课程 腹侧从中央后带通过SII到岛叶皮质， 然后到达杏仁核，并通过鼻腔间接到达海马体 皮层 我们现在有证据表明，第二种途径类似于 枕颞通路的物体视觉 我们的神经行为学证据 表明双侧岛叶损伤导致严重的触觉识别 赤字，一致的建议，岛叶皮层是一个关键的 在触觉识别的顶叶-岛叶-边缘系统通路中连接， 占据了类似于区域TE的位置 视觉识别的枕-颞-边缘通路 通过记录 在接受选择的损伤的半球中，来自SII的神经元活动 部分后中心体代表，我们证明了损失 来自SII的相应表示，指示 从邮政中心地带到SII的信息。 一个意想不到的发现， 这项研究是，在中枢后损伤后，失活的SII 进行重大职能重组。 在另一个实验中， 在4只猴子中记录来自中央后带的神经元活动10 - 12 在代表上肢的背根被切断后几年。 的 结果表明，上肢的整个表现已经 由扩展的面部表示代替，扩展的顺序为 比以前想象的要大。 这两 涉及中枢神经系统扰动的实验， 导致了以前未被认识到的皮层可塑性程度， 成年哺乳动物，并建议重组的潜力更大， 中枢神经系统比周围神经系统的操作。

In a series of anatomical experiments, we have identified two routes by which somatosensory information reaches limbic structures important for somatic 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. A second route courses ventrally from the postcentral strip through SII to the insular cortex and then to the amygdala and indirectly to the hippocampus through rhinal cortex. We now have evidence that this second pathway is analogous to the occipitotemporal pathway for object vision. Our neurobehavioral evidence indicates that bilateral insular lesions cause a severe tactile recognition deficit, consis- tent 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. By recording neuronal activity from SII in hemispheres that received lesions of selected portions of the postcentral body representation, we demonstrated a loss of the corresponding representation from SII, indicating a serial flow of information from the postcentral strip to SII. An unexpected finding in this study was that, following a postcentral lesion, the deactivated SII region undergoes major functional reorganization. In another experiment we recorded neuronal activity from the postcentral strip in 4 monkeys 10-12 years after the dorsal roots representing the upper limb were severed. The results indicated that the entire representation of the upper limb had been replaced by an expanded face representation, an expansion an order of magnitude greater than previously thought possible. Both of these experiments, involving perturbations of the central nervous system, resulted in a previously unrecognized degree of cortical plasticity in adult mammals and suggest that the potential for reorganization is greater after central than peripheral nervous system manipulations.