Caregiver Cumulative Cortisol Mediates Deviations in Functional Connectivity in Infants: A Novel fNIRS Study

护理人员累积皮质醇介导婴儿功能连接偏差：一项新的 fNIRS 研究

• 批准号: 2884608
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2884608
• 关键词: Caregiver; Cumulative; Cortisol; Mediates; Deviations

The effects of chronic physiological stress on the developing infant brain have long been recorded by developmental scientists. Infants who have experienced chronic physiological stress, as elucidated from maternal physiological stress, have been found to have deviations from the "typical" developing brain's trajectories (Troller-Renfree, 2020). These alterations, usually consisting of an overabundance of low frequency EEG power and a relative paucity of high-frequency power, have been attributed to a developmental delay entitled the "maturational lag" which has been postulated to describe a delay in the development of central nervous system, and in particular, cortical development (Corning, Steffy, Anderson & Bowers, 1986). My past research has extended these findings, looking into the differentiations between EEG power growth curves of infants mediated by chronic caregiver stress and its implications on cortical development. Not much research has been done using functional brain imaging techniques to determine whether these electrophysiological and structural changes are also marked by changes in hemodynamic responses as well when comparing infants with caregivers with and without chronic stress, and my proposed research aims to be some of the first research to do so.Functional near infrared spectroscopy (fNIRS) is a relatively novel method in which scientists can elucidate data about the hemodynamic changes happening in the brain. Though fMRI is the most commonly used technique to study these changes, its bulky and static nature makes it difficult to use on infants. fNIRS is comparatively smaller and portable, and much more suited to research in infancy.This method makes inferences about the brain's cytoarchitecture by examining values of connectivity/synchrony between neurons as they communicate with each other across the brain. Many of these studies have been done using fMRI, but more recently, scientists have begun to use fNIRS to study functional connectivity in infants. Much of this research has been done in cases of psycho- and neuropathology, but non-pathological literature also exists.To gain more information about the changes that occur to the infant brain when impacted by chronic stress, and to find more information either confirming or challenging the maturational lag hypothesis, I propose that a differential functional connectivity study be carried out, comparing infants with caregivers with chronic stress with those with infants with caregivers without. Will caregiver stress influence functional connectivity development in infants? This study fits very well into the PIPKIN project that is currently ongoing within the Cambridge Baby Lab, which includes fNIRS scanning at one/two weeks post-birth, at 5 months and at 9 months. Caregiver stress will be determined via hair cortisol. Hair cortisol has been found to be a reliable measure of chronic stress levels (Ursache et al., 2017) and allows us to make inferences about the stress that the infants we study experience, without using an invasive measure to determine their cortisol levels. An appropriate pipeline must be determined for the description of fNIRS functional connectivity but for now I point to the methods used in Gao et al., 2014, which identified 9 functional networks in fcMRI and was able to make inferences about their relative maturation via 3 quantitative measures: within-network connectivity, outside-network connectivity and overall similarity to adult references. After collection of resting data from each infant, and collecting hair samples from the caregiver, I will conduct a statistical analysis comparing the groups (high hair cortisol against low hair cortisol) to determine whether any significant differences arise between them in each functional network as well as carry out power analyses to determine whether correlations occur between magnitude of potential difference and difference in hair cortisol levels.

长期以来，发育科学家一直记录了慢性生理压力对发育中的婴儿大脑的影响。已经发现，经历过慢性生理压力的婴儿，从孕产妇的生理压力中阐明，与“典型”发育中的大脑轨迹有偏差（Troller-Renfree，2020年）。这些变化通常包括低频脑电图功率过多和高频功率的相对缺乏，归因于标题为“成熟滞后”的发育延迟，该延迟被认为是为了描述中枢神经的发展延迟系统，特别是皮质开发（Corning，Steffy，Anderson＆Bowers，1986）。我过去的研究扩展了这些发现，研究了由慢性护理人员压力介导的婴儿的脑电图生长曲线及其对皮质发育的影响。使用功能性脑成像技术进行的研究并没有进行太多的研究来确定这些电生理和结构变化是否也是由血液动力学反应的变化标记，而在将婴儿与具有和没有慢性压力的护理人员进行比较时，我提出的研究旨在成为一些研究。首次研究。功能近红外光谱（FNIRS）是一种相对新颖的方法，科学家可以阐明有关大脑中血流动力学变化的数据。尽管fMRI是研究这些变化的最常用技术，但其庞大和静态的性质使其难以在婴儿身上使用。 FNIRS相对较小且可移植，并且更适合于婴儿期进行研究。这种方法通过检查神经元之间的连通性/同步值相互交流，从而推断出大脑的细胞结构。这些研究中的许多研究都是使用fMRI进行的，但是最近，科学家开始使用FNIRS研究婴儿的功能连通性。这项研究的大部分是在心理和神经病理学的情况下进行的，但是非病理学文献也存在。要获得有关在受长期压力影响时婴儿大脑发生的变化的更多信息，并找到更多信息确认或确认。挑战成熟的滞后假说，我建议进行一项差异功能连通性研究，将患有患有慢性压力的护理人员与患有护理人员的婴儿进行比较。照顾者的压力会影响婴儿的功能连通性发展吗？这项研究非常适合PIPKIN项目，该项目目前正在剑桥婴儿实验室内进行，其中包括在出生后一/两周，5个月和9个月的fnirs扫描。护理人员应力将通过头发皮质醇确定。已经发现皮质醇是慢性应激水平的可靠度量（Ursache等，2017），并使我们能够推断出我们研究经验的婴儿而无需使用侵入性措施来确定其皮质醇水平的压力。必须确定适当的管道来描述FNIRS功能连接性，但就目前，我指出了Gao等人（2014年）中使用的方法，该方法在FCMRI中识别了9个功能网络，并且能够通过3个定量来推断其相对成熟措施：网络内连接性，外部网络连通性以及与成人参考的总体相似性。在收集了每个婴儿的静息数据并从护理人员那里收集头发样本后，我将进行统计分析，以比较这些组（高毛皮质醇与低毛皮质醇），以确定每个功能网络中它们之间是否也出现任何显着差异随着执行功率分析，以确定在势差和头发皮质醇水平差之间是否发生相关性。