Functional MRI Responses to Passive, Active, and Observed Touch in Somatosensory and Insular Cortices of the Macaque Monkey
Functional MRI Responses to Passive, Active, and Observed Touch in Somatosensory and Insular Cortices of the Macaque Monkey
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DOI：
10.1523/jneurosci.1587-17.2018
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发表时间：
2018-04-11
影响因子：
5.3
通讯作者：
Nelissen, Koen
中科院分区：
文献类型：
--
作者：
Sharma, Saloni;Fiave, Prosper A.;Nelissen, Koen
从灵长类动物身上获得的神经生理学数据表明，仅仅观察他人的行为就可以调节观察者运动皮层的活动。在人类中，已经有人提出，这些多模态替代反应远远超出了运动皮层，包括体感和岛脑区域，当目睹他人的行为，感觉或情绪时，这些区域似乎会产生替代反应（Gazzola和Keysers，2009）。尽管在猴子运动系统中共享动作反应的数据丰富，但在观察触摸过程中，体感和岛叶皮层是否也产生替代反应仍然是未知的。使用独立的触觉和运动功能磁共振成像定位器，我们首先映射了两只雄性猴子的初级（SI）和次级（SII）躯体感觉皮层的手代表。在随后的两个视觉实验中，我们检查了fMRI大脑对（1）观察同种的手被触摸或（2）观察人手抓住或仅仅触摸物体或另一只人手的反应。虽然功能定义的“触觉SI”和“触觉SII”在代表观察到的触摸方面几乎没有参与，但在顶叶区PFG中发现了触摸的替代反应，这与最近在人类中的观察结果一致（Chan和Baker，2015）。有趣的是，更前部的SII，和后岛叶皮层，这两个响应时，猴子进行主动抓取运动，也产生了视觉反应，在不同的情况下，触摸观察。
Neurophysiological data obtained in primates suggests that merely observing others' actions can modulate activity in the observer's motor cortices. In humans, it has been suggested that these multimodal vicarious responses extend well beyond the motor cortices, including somatosensory and insular brain regions, which seem to yield vicarious responses when witnessing others' actions, sensations, or emotions (Gazzola and Keysers, 2009). Despite the wealth of data with respect to shared action responses in the monkey motor system, whether the somatosensory and insular cortices also yield vicarious responses during observation of touch remains largely unknown. Using independent tactile and motor fMRI localizers, we first mapped the hand representations of two male monkeys' primary (SI) and secondary (SII) somatosensory cortices. In two subsequent visual experiments, we examined fMRI brain responses to (1) observing a conspecific's hand being touched or (2) observing a human hand grasping or mere touching an object or another human hand. Whereas functionally defined "tactile SI" and "tactile SII" showed little involvement in representing observed touch, vicarious responses for touch were found in parietal area PFG, consistent with recent observations in humans (Chan and Baker, 2015). Interestingly, a more anterior portion of SII, and posterior insular cortex, both of which responded when monkeys performed active grasping movements, also yielded visual responses during different instances of touch observation.