Brain iron is vital for core neurodevelopmental processes including myelination and neurotransmitter synthesis and, accordingly, iron accumulates in the brain with age. However, little is known about the association between brain iron and neural functioning and how they evolve with age in early infancy. This study investigated brain iron in 48 healthy infants (22 females) aged 64.00 ± 33.28 days by estimating R2 * relaxometry from multi-echo functional MRI (fMRI). Linked independent component analysis was performed to examine the association between iron deposition and spontaneous neural activity, as measured by the amplitude of low frequency fluctuations (ALFF) by interrogating shared component loadings across modalities. Further, findings were validated in an independent dataset (n = 45, 24 females, 77.93 ± 26.18 days). The analysis revealed developmental coupling between the global R2 * and ALFF within the default mode network (DMN). Furthermore, we observed that this coupling effect significantly increased with age (r = 0.78, p = 9.2e-11). Our results highlight the importance of iron-neural coupling during early development and suggest that the neural maturation of the DMN may correspond to growth in distributed brain iron.

脑铁对于包括髓鞘形成和神经递质合成在内的核心神经发育过程至关重要，因此，铁会随着年龄的增长而在大脑中积累。然而，人们对脑铁与神经功能之间的关联以及它们如何随着婴儿早期年龄的变化而了解甚少。本研究通过多回波功能 MRI (fMRI) 估算 R2 * 弛豫测量，调查了 48 名年龄为 64.00 ± 33.28 天的健康婴儿（22 名女性）的脑铁含量。进行关联独立成分分析，以检查铁沉积与自发神经活动之间的关联，通过询问跨模式的共享成分负荷，通过低频波动 (ALFF) 的幅度来测量。此外，研究结果在独立数据集中得到了验证（n = 45，24 名女性，77.93 ± 26.18 天）。分析揭示了默认模式网络 (DMN) 内全局 R2 * 和 ALFF 之间的发展耦合。此外，我们观察到这种耦合效应随着年龄的增长而显着增加（r  = 0.78，p  = 9.2e-11）。我们的结果强调了铁-神经耦合在早期发育过程中的重要性，并表明 DMN 的神经成熟可能与分布式脑铁的生长相对应。