Role of Peripheral & Brain Iron in the Development of Attention & Cognitive Control

项目总结 一项新的研究表明儿童外化障碍与缺铁有关 以注意力和认知控制缺陷为特征，如注意力缺陷/多动症 精神障碍(ADHD)和对抗性违抗性障碍。在儿童中，缺铁是 假设是由于铁在合成中的关键作用而导致了这些缺陷 以及重要的神经递质，如多巴胺和去甲肾上腺素，在 纹状体的功能，以及额叶的髓鞘形成，所有这些都是 与ADHD患者的注意力和认知控制障碍有关。之前的研究已经 在评估这些相关性时，很大程度上利用了外周(基于血液的)铁指标； 然而，外围铁的测量可能不能准确地反映体内的铁浓度。 大脑。神经成像方法的最新发展现在允许非侵入性、 组织磁化率差异的超高分辨率地图，这与 与灰质中的组织铁浓度密切相关。到目前为止只有两项研究 评估了脑铁浓度和注意力障碍之间的关系 通过神经成像对儿童的认知控制，两者都提供了初步证据 患有ADHD症状的学龄儿童脑铁减少。的目标是 提出的项目是为了更好地了解脑铁的早期发育过程 儿童的注意力集中及其与关键认知系统的关系 把行为问题外化。为了实现这一目标，我们将招募40名儿童 6至8岁，其中一半有缺铁病史(测量 外围)处于婴儿期，其中一半人没有。参赛者将完成：1)高 7特斯拉分辨率神经成像研究以估计同时存在的脑铁浓度；2) 抽血以评估并发的外周铁浓度；以及3)聚焦的 用于评估同时注意和认知控制的神经心理评估，如 以及其他认知系统(例如，语言和视觉感知) 推测受早期缺铁的影响较小。此外，参与者的父母 教师将被要求完成与缺陷相关的行为的评级 注意力和认知控制。这项研究是解剖学成像技术的首次应用。 评估幼儿脑铁浓度的技术，与早期 外周铁指数，以确定铁状态与批判性认知的关系 系统。

PROJECT SUMMARY Emerging research implicates iron deficiency in childhood externalizing disorders featuring deficits in attention and cognitive control, such as Attention-Deficit/Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder. In children, iron deficiency is hypothesized to contribute to these deficits as a result of iron’s critical role in the synthesis and expression of important neurotransmitters such as dopamine and norepinephrine, in the functioning of the striatum, and in myelination of the frontal lobe, all of which have been linked to impairment in attention and cognitive control in ADHD. Previous research has largely utilized peripheral (blood-based) iron measures in evaluating these associations; however, peripheral iron measures may not accurately represent iron concentrations in the brain. Recent developments in neuroimaging methodologies now allow for non-invasive, ultra-high resolution maps of tissue magnetic susceptibility differences, which correlate strongly with tissue iron concentrations in gray matter. Only two studies to date have assessed the relationship between brain iron concentrations and disorders of attention and cognitive control in children via neuroimaging, with both providing preliminary evidence of reduced brain iron among school-aged children with ADHD symptomatology. The goal of the proposed project is to better understand the early developmental course of brain iron concentration in (human) children and its relationship to critical cognitive systems implicated in externalizing behavior problems. To accomplish this goal, we will recruit 40 children between the ages of 6 and 8 years, half of whom have a history of iron deficiency (measured peripherally) in infancy and half of whom do not. Participants will complete: 1) a high resolution neuroimaging study at 7 Tesla to estimate concurrent brain iron concentrations; 2) a blood draw to assess concurrent peripheral iron concentrations; and 3) a focused neuropsychological assessment to evaluate concurrent attention and cognitive control, as well as other cognitive systems (e.g., language and visual perception) which are hypothesized to be less impacted by early iron deficiency. In addition, participants’ parents and teachers will be asked to complete ratings of behaviors associated with deficits in attention and cognitive control. This study represents the first use of anatomic imaging techniques to evaluate brain iron concentrations in young children, in association with early peripheral iron indices, to determine the relation between iron status and critical cognitive systems.