Wang X, Merzenich M M, Sameshima K, Jenkins W M
Coleman Laboratory, University of California at San Francisco 94143, USA.
Nature. 1995 Nov 2;378(6552):71-5. doi: 10.1038/378071a0.
The primate somatosensory cortex, which processes tactile stimuli, contains a topographic representation of the signals it receives, but the way in which such maps are maintained is poorly understood. Previous studies of cortical plasticity indicated that changes in cortical representation during learning arise largely as a result of hebbian synaptic change mechanisms. Here we show, using owl monkeys trained to respond to specific stimulus sequence events, that serial application of stimuli to the fingers results in changes to the neuronal response specificity and maps of the hand surfaces in the true primary somatosensory cortical field (S1 area 3b). In this representational remodelling stimuli applied asychronously to the fingers resulted in these fingers being integrated in their representation, whereas fingers to which stimuli were applied asynchronously were segregated in their representation. Ventroposterior thalamus response maps derived in these monkeys were not equivalently reorganized. This representational plasticity appears to be cortical in origin.
处理触觉刺激的灵长类动物体感皮层包含其所接收信号的拓扑表征，但人们对这种图谱的维持方式了解甚少。此前关于皮层可塑性的研究表明，学习过程中皮层表征的变化主要是由赫布突触变化机制引起的。在这里，我们使用经过训练对特定刺激序列事件做出反应的猫头鹰猴进行研究，结果表明，对手指进行连续刺激会导致真正的初级体感皮层区域（S1区3b）中神经元反应特异性和手部表面图谱发生变化。在这种表征重塑过程中，异步施加于手指的刺激会使这些手指在其表征中整合在一起，而异步施加刺激的手指则在其表征中被分隔开来。在这些猴子身上得到的丘脑腹后核反应图谱并没有发生同等程度的重组。这种表征可塑性似乎起源于皮层。
