ACUTE CHANGES IN CUTANEOUS RECEPTIVE-FIELDS IN PRIMARY SOMATOSENSORY CORTEX AFTER DIGIT DENERVATION IN ADULT FLYING FOX
ACUTE CHANGES IN CUTANEOUS RECEPTIVE-FIELDS IN PRIMARY SOMATOSENSORY CORTEX AFTER DIGIT DENERVATION IN ADULT FLYING FOX
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DOI：
10.1152/jn.1991.65.2.178
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发表时间：
1991-02-01
影响因子：
2.5
通讯作者：
TWEEDALE, R
中科院分区：
文献类型：
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作者：
CALFORD, MB;TWEEDALE, R
1.急性效应的永久性和暂时性去神经的狐蝠拇指进行了检查，以测试的假设，皮肤周围的大面积的多单位（MRF）在初级体感皮层（SI）的一个位点的皮肤感受野提供可行的输入，可以迅速揭开的中断占主导地位的输入从该地区的MRF。在原始感受野完全被移除的部位切断拇指的直接影响是在邻近的身体区域（手腕、前臂、前翅和手指膜）产生大的MRF。当截肢仅切除皮质部位的部分原始MRF时，也会产生极大扩展的MRF。新的感受野可能的输入来源是躯体感觉通路内的上行投射的广泛分支，这些分支从比正常感受野所代表的区域大得多的区域向皮层位点提供潜在的输入。在去神经支配后，新的或扩大的视野被看到的速度表明，在感受野周围通常未表达的输入不仅是潜在的输入，而且是固有的可行性。因此，对这项研究结果最可能的解释是，去神经支配的效果是破坏了通常具有塑造感受野作用的抑制影响。全部或部分MRF的暂时麻醉产生与截肢相似的初始效果。当局部麻醉区域的反应性恢复时（10-30分钟后），MRF持续扩张一段短时间，之后MRF的边界缩小。这种快速逆转表明，一个机械的，而不是塑料的变化是一个小的去神经SI的急性影响的基础。
1. Acute effects of permanent and temporary denervation of the flying fox thumb were examined to test the hypothesis that a large area of skin around the cutaneous receptive field of multi-units (MRF) at a locus in primary somatosensory cortex (SI) supplies viable inputs which can be rapidly unmasked by interruption of the dominant input from the area of the MRF.2. The immediate effect of amputation of the thumb at loci where the original receptive field was entirely removed was to produce large MRFs on adjacent body areas (wrist, forearm, prowing, and finger membranes). Greatly expanded MRFs were also produced when amputation removed only part of the original MRF at a cortical locus.3. The probable source of input to account for the new receptive field is the extensive arborization of ascending projections within the somatosensory pathway, which supply a cortical locus with a potential input from a far larger area than is represented in its normal receptive field. The rapidity with which new or expanded fields are seen following denervation indicates that the normally unexpressed inputs around a receptive field are not only potential inputs but are inherently viable. Hence the most likely explanation for the results of this study is that the effect of the denervation is to disrupt an inhibitory influence that normally has the role of shaping the receptive field.4. Temporary anesthesia of all or part of a MRF produced similar initial effects to amputation. When responsiveness returned to the locally anesthetized area (after 10-30 min), an expanded MRF persisted for a short time after which the boundaries of the MRF shrank. This rapid reversal suggests that a mechanistic rather than a plastic change is the basis for the acute effect of a small denervation on SI.