Functional reorganisation and recovery following cortical lesions: A study in macaque monkeys
Functional reorganisation and recovery following cortical lesions: A study in macaque monkeys
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DOI：
10.1101/202192
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发表时间：
2017-10
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影响因子：
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通讯作者：
Matthew Ainsworth;Helen Browncross;Daniel J. Mitchell;Anna S. Mitchell;R. Passingham;M. Buckley;J. Duncan;A. Bell
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文献类型：
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作者：
Matthew Ainsworth;Helen Browncross;Daniel J. Mitchell;Anna S. Mitchell;R. Passingham;M. Buckley;J. Duncan;A. Bell
创伤性脑损伤或中风后的损伤通常会超出最初损伤的范围，并可能导致适应不良的皮质重组。另一方面，也可能发生有益的皮质重组，导致功能恢复。在这里，我们使用静息态功能磁共振成像 (rsFMRI) 来检查猕猴大脑的功能连接如何随着时间的推移而变化，以响应前额皮质的损伤，以及这种重组如何与行为变化相关。两只猴子被训练执行基于位置和基于对象的延迟匹配样本任务。我们还在全身麻醉下收集了相隔 3-4 周的两个病变前时间点的 rsFMRI 数据。经过两个周期的测试和扫描后，动物出现主沟病变，然后再进行 4 个周期的测试和扫描。后来，同样的动物在另一半球接受了第二次损伤，并进行了额外的测试和扫描周期。两只动物在第一次病变后均表现出明显的行为障碍，这与功能连接的减少有关，主要是在两个半球的额叶网络中。病变后大约 8 周，性能得到改善，这些网络内的功能连接也得到改善。第二次损伤后，功能连接再次下降，这与未恢复的边际行为缺陷有关。我们的数据表明，行为障碍不仅反映了病变区域的去除，还反映了对广泛皮质网络的干扰。该网络可以通过恢复和/或加强预先存在的连接来恢复，从而改善行为。
Damage following traumatic brain injury or stroke can often extend beyond the boundaries of the initial insult and can lead to maladaptive cortical reorganisation. On the other hand, beneficial cortical reorganisation leading to recovery of function can also occur. Here, we used resting state FMRI (rsFMRI) to examine how functional connectivity in the macaque brain changed across time in response to lesions to the prefrontal cortex, and how this reorganisation correlated with changes in behaviour. Two monkeys were trained to perform location-based and object-based delayed match-to-sample tasks. We also collected rsFMRI data under general anaesthesia at two pre-lesion time-points, separated by 3-4 weeks. After two cycles of testing and scanning, the animals received a principal sulcus lesion followed by an additional 4 cycles of testing and scanning. Later, the same animals received a second lesion to the opposite hemisphere and additional cycles of testing and scanning. Both animals showed a marked behavioural impairment following the first lesion, which was associated with a decrease in functional connectivity, predominantly within frontal-frontal networks in both hemispheres. Approximately 8 weeks following the lesion, performance improved, as did functional connectivity within these networks. Following the second lesion, functional connectivity again decreased and this was associated with a marginal behavioural deficit that did not recover. Our data show that behavioural impairments reflect not just the removal of the lesioned area, but also disturbance to an extensive cortical network. This network can recover by restoring and/or strengthening pre-existing connections, leading to improvement in behaviour.