National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; School of System Science, Beijing Normal University, Beijing 100875, China.
Neuroimage. 2024 Oct 1;299:120844. doi: 10.1016/j.neuroimage.2024.120844. Epub 2024 Sep 10.
Congenital blindness offers a unique opportunity to investigate human brain plasticity. The influence of congenital visual loss on the asymmetry of the structural network remains poorly understood. To address this question, we recruited 21 participants with congenital blindness (CB) and 21 age-matched sighted controls (SCs). Employing diffusion and structural magnetic resonance imaging, we constructed hemispheric white matter (WM) networks using deterministic fiber tractography and applied graph theory methodologies to assess topological efficiency (i.e., network global efficiency, network local efficiency, and nodal local efficiency) within these networks. Statistical analyses revealed a consistent leftward asymmetry in global efficiency across both groups. However, a different pattern emerged in network local efficiency, with the CB group exhibiting a symmetric state, while the SC group showed a leftward asymmetry. Specifically, compared to the SC group, the CB group exhibited a decrease in local efficiency in the left hemisphere, which was caused by a reduction in the nodal properties of some key regions mainly distributed in the left occipital lobe. Furthermore, interhemispheric tracts connecting these key regions exhibited significant structural changes primarily in the splenium of the corpus callosum. This result confirms the initial observation that the reorganization in asymmetry of the WM network following congenital visual loss is associated with structural changes in the corpus callosum. These findings provide novel insights into the neuroplasticity and adaptability of the brain, particularly at the network level.
先天性失明为研究人类大脑可塑性提供了独特的机会。先天性视觉丧失对结构网络不对称性的影响仍知之甚少。为了解决这个问题，我们招募了 21 名先天性失明（CB）患者和 21 名年龄匹配的视力正常对照组（SCs）。我们使用扩散张量成像和结构磁共振成像，通过确定性纤维追踪构建了半球白质（WM）网络，并应用图论方法评估了这些网络中的拓扑效率（即网络全局效率、网络局部效率和节点局部效率）。统计分析显示，两组的全局效率都存在一致的左侧不对称性。然而，在网络局部效率方面出现了不同的模式，CB 组呈对称状态，而 SC 组呈左侧不对称。具体来说，与 SC 组相比，CB 组在左侧半球的局部效率降低，这是由于一些主要分布在左枕叶的关键区域的节点属性降低所致。此外，连接这些关键区域的半球间束表现出显著的结构变化，主要发生在胼胝体压部。这一结果证实了最初的观察结果，即先天性视觉丧失后 WM 网络的不对称性重组与胼胝体的结构变化有关。这些发现为大脑的神经可塑性和适应性提供了新的见解，特别是在网络层面。
