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.
22Damage following traumatic brain injury or stroke can often extend beyond the boundaries of the 23 initial insult and can lead to maladaptive cortical reorganisation. On the other hand, beneficial cortical 24 reorganisation leading to recovery of function can also occur. Here, we used resting state FMRI (rsFMRI) to 25 examine how functional connectivity in the macaque brain changed across time in response to lesions to the 26 prefrontal cortex, and how this reorganisation correlated with changes in behaviour. Two monkeys were 27 trained to perform location-based and object-based delayed match-to-sample tasks. We also collected 28 rsFMRI data under general anaesthesia at two pre-lesion time-points, separated by 3-4 weeks. After two 29 cycles of testing and scanning, the animals received a principal sulcus lesion followed by an additional 4 cycles 30 of testing and scanning. Later, the same animals received a second lesion to the opposite hemisphere and 31 additional cycles of testing and scanning. 32Both animals showed a marked behavioural impairment following the first lesion, which was 33 associated with a decrease in functional connectivity, predominantly within frontal-frontal networks in both this was associated with a marginal behavioural deficit that did not recover. 37Our data show that behavioural impairments reflect not just the removal of the lesioned area, but 38 also disturbance to an extensive cortical network. This network can recover by restoring and/or 39 strengthening pre-existing connections, leading to improvement in behaviour.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.