Large-scale reorganization in the somatosensory cortex and thalamus after sensory loss in macaque monkeys.
Large-scale reorganization in the somatosensory cortex and thalamus after sensory loss in macaque monkeys.
复制标题
DOI：
10.1523/jneurosci.2334-08.2008
复制
发表时间：
2008-10-22
影响因子：
5.3
通讯作者：
Kaas, Jon H.
中科院分区：
文献类型：
--
作者：
Jain, Neeraj;Qi, Hui-Xin;Collins, Christine E.;Kaas, Jon H.
成年人的大脑经历了大规模的可塑性变化后，外周和中央损伤。虽然已经证明皮层和丘脑的表征都可以重组，但关于每个层次变化的程度、性质和时间过程存在不确定性。我们已经确定了如何在体感区3b和丘脑腹后（VP）核皮质代表长期存在的单方面背柱病变在猕猴的颈部水平的影响。在恢复期为22 - 23个月的猴子中，完整的面部输入在背柱完全或部分损伤后扩展到3b区的去传入手区域。面部区域的扩展可以一直向内侧延伸到腿部和足部表示中。在同一只猴子中，丘脑的VP核也发生了类似的面部表征扩展，这表明这两个处理水平都经历了类似的重组。扩展表征的感受野在躯体感觉皮层和丘脑中相似。在两只猴子中，我们确定了背柱损伤后大脑重组的程度。在这些猴子中，3b区和VP核的去传入区域在损伤后立即对外周触摸无反应。在皮质或VP核中未观察到重组。通过比较猴子的传入神经阻滞程度，我们发现，即使背柱损伤是局部的，保留了大部分的手表征，也足以引起面部表征的扩张。
Adult brains undergo large-scale plastic changes following peripheral and central injuries. Although it has been shown that both the cortical and thalamic representations can reorganize, uncertainties exist regarding the extent, nature, and time course of changes at each level. We have determined how cortical representations in the somatosensory area 3b and the ventroposterior (VP) nucleus of thalamus are affected by long standing unilateral dorsal column lesions at cervical levels in macaque monkeys. In monkeys with recovery periods of 22-23 months, the intact face inputs expanded into the deafferented hand region of area 3b following complete or partial lesions of the dorsal columns. The expansion of the face region could extend all the way medially into the leg and foot representations. In the same monkeys, similar expansions of the face representation take place in the VP nucleus of the thalamus, indicating that both these processing levels undergo similar reorganizations. The receptive fields of the expanded representations were similar in somatosensory cortex and thalamus. In two monkeys, we determined the extent of the brain reorganization immediately after dorsal column lesions. In these monkeys, the deafferented regions of area 3b and the VP nucleus became unresponsive to the peripheral touch immediately after the lesion. No reorganization was seen in the cortex or the VP nucleus. A comparison of the extents of deafferentation across the monkeys shows that even if the dorsal column lesion is partial, preserving most of the hand representation, it is sufficient to induce an expansion of the face representation.