Department of Neurology, University Medical Centre Ljubljana, Zaloška 2a, 1000 Ljubljana, Slovenia; Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia.
Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia; Institute of Clinical Neurophysiology, University Medical Centre Ljubljana, Zaloška 7, 1000 Ljubljana, Slovenia; Institute of Radiology, University Medical Centre Ljubljana, Zaloška 7, 1000 Ljubljana, Slovenia.
J Neurol Sci. 2021 Jun 15;425:117443. doi: 10.1016/j.jns.2021.117443. Epub 2021 Apr 9.
Neurodegeneration leads to redistribution of processing, which is reflected in a reorganisation of the structural connectome. This might affect its vulnerability to structural damage. Cortical acetylcholine allows favourable adaptation to pathology within the memory circuit. However, it remains unclear if it acts on a broader scale, affecting reconfiguration of whole-brain networks. To investigate the role of the cholinergic basal forebrain (CBFB) in strategic lesions, twenty patients with mild cognitive impairment (MCI) and twenty elderly controls underwent magnetic resonance imaging. Whole-brain tractograms were represented as network graphs. Lesions of individual nodes were simulated by removing a node and its connections from the graph. The impact of simulated lesions was quantified as the proportional change in global efficiency. Relationships between subregional CBFB volumes, global efficiency of intact connectomes and impacts of individual simulated lesions of network nodes were assessed. In MCI but not controls, larger CBFB volumes were associated with efficient network topology and reduced impact of hippocampal, thalamic and entorhinal lesions, indicating a protective effect against the global impact of simulated strategic lesions. This suggests that the cholinergic system shapes the configuration of the connectome, thereby reducing the impact of localised damage in MCI.
神经退行性变导致处理过程重新分配，这反映在结构连接组的重新组织中。这可能会影响其对结构损伤的脆弱性。皮质乙酰胆碱允许在记忆回路的病理变化中进行有利的适应。然而，目前尚不清楚它是否在更广泛的范围内发挥作用，影响整个大脑网络的重新配置。为了研究基底前脑胆碱能（CBFB）在策略性病变中的作用，二十名轻度认知障碍（MCI）患者和二十名老年对照组接受了磁共振成像。全脑束描记术被表示为网络图。通过从图中删除节点及其连接来模拟单个节点的损伤。通过模拟损伤的影响被量化为全局效率的比例变化。评估了 CBFB 亚区体积、完整连接组的全局效率与网络节点的单个模拟损伤的影响之间的关系。在 MCI 中，但不是在对照组中，更大的 CBFB 体积与有效的网络拓扑结构相关，并且减少了海马体、丘脑和内嗅皮质损伤的影响，表明对模拟策略性损伤的全局影响具有保护作用。这表明胆碱能系统塑造了连接组的结构，从而降低了 MCI 中局部损伤的影响。
