Merrill Palmer Skillman Institute for Child and Family Development, Wayne State University, Detroit, MI, 48202, USA.
Beckman Institute for Advanced Science and Technology at the University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
Dev Cogn Neurosci. 2018 Nov;34:18-26. doi: 10.1016/j.dcn.2018.05.004. Epub 2018 May 22.
Non-heme iron is a vital metabolic cofactor for many core processes of brain development including myelination, dendritogenesis, and neurotransmitter synthesis, and accumulates in the brain with age. However, little is known about development-related differences in brain iron and its association with emerging cognitive abilities during formative years. In this study, we estimated brain iron via R2* relaxometry in children ages 7-16 (N = 57; 38 females) and examined its relation to age-related differences in cognitive ability. As we hypothesized, age correlated positively with iron content in the hippocampus and across subregions of the basal ganglia. The magnitude of age differences in iron content differed between regions such that the largest effects were observed in basal ganglia subregions: globus pallidus, substantia nigra, caudate nucleus, and putamen, as compared to values obtained for the hippocampus and red nucleus. We did not observe sex or hemispheric differences in iron content. Notably, greater brain iron content was associated with both faster processing speed and higher general intelligence, and shared 21.4% of the age-related improvement in processing speed and 12.5% of the improvement in general intelligence. These results suggest that non-heme iron plays a central neurobiological role in the development of critical cognitive abilities during childhood.
非血红素铁是大脑发育许多核心过程的重要代谢辅助因子，包括髓鞘形成、树突发生和神经递质合成，并随着年龄的增长在大脑中积累。然而，对于与年龄相关的大脑铁含量差异及其与形成期认知能力的关系，人们知之甚少。在这项研究中，我们通过 R2*弛豫率测量法在 7-16 岁儿童（N=57；38 名女性）中估计了大脑铁含量，并研究了其与认知能力的年龄相关差异之间的关系。正如我们假设的那样，年龄与海马体和基底节各区域的铁含量呈正相关。铁含量的年龄差异在不同区域之间存在差异，例如，基底节的各个区域（苍白球、黑质、尾状核和壳核）的影响最大，而与海马体和红核的结果相比。我们没有观察到铁含量的性别或半球差异。值得注意的是，大脑铁含量越高，处理速度越快，一般智力越高，并且与处理速度的年龄相关性提高有关（提高了 21.4%），与一般智力的提高有关（提高了 12.5%）。这些结果表明，非血红素铁在儿童期关键认知能力的发展中起着核心的神经生物学作用。
