Chronically Deafferented Sensory Cortex Recovers a Grossly Typical Organization after Allogenic Hand Transplantation
Chronically Deafferented Sensory Cortex Recovers a Grossly Typical Organization after Allogenic Hand Transplantation
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DOI：
10.1016/j.cub.2008.08.051
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发表时间：
2008-10-14
期刊：
影响因子：
9.2
通讯作者：
Breidenbach, Warren C.
中科院分区：
文献类型：
--
作者：
Frey, Scott H.;Bogdanov, Sergei;Breidenbach, Warren C.
截肢后，初级感觉皮层(S1复合体，以下简称S1复合体)的躯体结构发生实质性重组[1，2]，这些去神经化作用随着时间的延长而增强[3]。确定这些变化是否是可逆的，对于了解从去传入损伤中恢复的潜力至关重要。早期的BOLD功能磁共振成像数据显示，同种异体移植手刺激后，S1活性增加[4]。在这里，我们报告了第一个证据，即移植的手的代表实际上可以重新获得截肢前的S1手领土。一位54岁的男性在右手创伤性截肢35年后接受了单侧手移植。尽管感觉有限，但在移植后4个月，掌部触觉刺激引起的对侧S1反应在位置和幅度上与健康对照组检测到的反应没有什么区别。我们没有发现移植手的面部代表持续侵入的证据，尽管这种侵入在截肢者中很常见[5，6]。我们的结果表明，即使在完全去感觉化的几十年后，恢复对S1的传入输入也会导致在其原始区域内重新建立粗略的手表征。出乎意料的是，大的同侧S1反应伴随着患者完整的手的感觉刺激。这可能反映了大脑半球间抑制的变化，这可能有助于在截肢期间保持潜在的手表征。
Amputation induces substantial reorganization of the body part somatotopy in primary sensory cortex (S1 complex, hereafter S1) [1, 2], and these effects of deafferentiation increase with time [3]. Determining whether these changes are reversible is critical for understanding the potential to recover from deafferenting injuries. Earlier BOLD fMRI data demonstrate increased S1 activity in response to stimulation of an allogenically transplanted hand [4]. Here, we report the first evidence that the representation of a transplanted hand can actually recapture the pre-amputation S1 hand territory. A 54-year-old male received a unilateral hand transplant 35 years after traumatic amputation of his right hand. Despite limited sensation, palmar tactile stimulation delivered 4 months post-transplant evoked contralateral S1 responses that were indistinguishable in location and amplitude from those detected in healthy matched controls. We find no evidence for persistent intrusion of representations of the face within the representation of the transplanted hand, although such intrusions are commonly reported in amputees [5, 6]. Our results suggest that even decades after complete deafferentiation, restoring afferent input to S1 leads to re-establishment of the gross hand representation within its original territory. Unexpectedly, large ipsilateral S1 responses accompanied sensory stimulation of the patient's intact hand. These may reflect a change in interhemispheric inhibition that could contribute to maintaining latent hand representations during the period of amputation.