Functional homotopy reflects the link between spontaneous activity in a voxel and its counterpart in the opposite hemisphere. Alterations in homotopic functional connectivity (FC) are seen in normal aging, with highest and lowest homotopy being present in sensory-motor and higher-order regions, respectively. Homotopic FC relates to underlying structural connections, but its neurobiological underpinnings remain unclear. The genu of the corpus callosum joins symmetrical parts of the prefrontal cortex (PFC) and is susceptible to age-related degeneration, suggesting that PFC homotopic connectivity is linked to changes in white-matter integrity. We investigated homotopic connectivity changes and whether these were associated with white-matter integrity in 338 individuals. In addition, we examined whether PFC homotopic FC was related to changes in the genu over 10 years and working memory over 5 years. There were increases and decreases in functional homotopy, with the former being prevalent in subcortical and frontal regions. Increased PFC homotopic FC was partially driven by structural degeneration and negatively associated with working memory, suggesting that it reflects detrimental age-related changes.

中文翻译：

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前额叶皮层功能同伦增加与胼胝体退化和工作记忆衰退有关

功能同伦反映了体素中的自发活动与其对侧半球的对应物之间的联系。在正常衰老中可以看到同伦功能连接 (FC) 的变化，最高和最低的同伦分别出现在感觉运动和高阶区域。同位 FC 与潜在的结构连接有关，但其神经生物学基础仍不清楚。胼胝体的膝部连接前额叶皮层 (PFC) 的对称部分，并且容易发生与年龄相关的退化，这表明 PFC 同位连接与白质完整性的变化有关。我们调查了 338 个人的同伦连接变化以及这些变化是否与白质完整性相关。此外，我们检查了 PFC 同位 FC 是否与超过 10 年的膝部变化和超过 5 年的工作记忆有关。功能同伦有增有减，前者普遍存在于皮层下和额叶区域。增加的 PFC 同位 FC 部分是由结构退化驱动的，并且与工作记忆负相关，表明它反映了有害的与年龄相关的变化。