MRC Cognition and Brain Sciences Unit, University of Cambridge, 15 Chaucer Road, Cambridge, UK.
Dept. of Experimental Psychology, University of Oxford, Parks Road, Oxford, UK.
Neuropsychologia. 2018 Oct;119:382-391. doi: 10.1016/j.neuropsychologia.2018.08.024. Epub 2018 Sep 12.
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. We used resting state FMRI to investigate how cortical networks in the macaque brain change across time in response to lesions to the prefrontal cortex, and how this reorganisation correlated with changes in behavioural performance in cognitive tasks. After prelesion testing and scanning, two monkeys received a lesion to regions surrounding the left principal sulcus followed by periodic testing and scanning. Later, the animals received another lesion to the opposite hemisphere and additional testing and scanning. Following the first lesion, we observed both a behavioural impairment and decrease in functional connectivity, predominantly in frontal-frontal networks. Approximately 8 weeks later, performance and connectivity patterns both improved. Following the second lesion, we observed a further behavioural deficit and decrease in connectivity that showed little recovery. We discuss how different mechanisms including alternate behavioural strategies and reorganisation of specific prefrontal networks may have led to improvements in behaviour. Further work will be needed to confirm these mechanisms.
创伤性脑损伤或中风后的损伤通常会超出初始损伤的范围，并导致适应性皮质重组。另一方面，也可能发生有益的皮质重组，从而导致功能恢复。我们使用静息状态 fMRI 来研究猕猴大脑中的皮质网络如何随时间变化以响应前额叶皮层的损伤，以及这种重组如何与认知任务中行为表现的变化相关。在损伤前测试和扫描后，两只猴子接受了左主沟周围区域的损伤，随后进行了定期测试和扫描。之后，动物接受了对侧半球的另一次损伤以及额外的测试和扫描。在第一次损伤后，我们观察到行为障碍和功能连接减少，主要在前额叶-前额叶网络中。大约 8 周后，表现和连接模式都有所改善。在第二次损伤后，我们观察到行为缺陷进一步加重，连接性下降，几乎没有恢复。我们讨论了包括替代行为策略和特定前额叶网络重组在内的不同机制如何导致行为改善。还需要进一步的工作来证实这些机制。
