儿童青少年时期脑功能连接梯度的发育规律

Development of functional connectome gradients during childhood and adolescence

成年人脑功能网络呈现从初级皮层到联合皮层渐变的核心连接梯度模式,支持了从初级感知觉到复杂抽象认知的信息加工过程.然而,目前对于人脑网络的初级皮层-联合皮层连接梯度如何发育,及其与认知发展、基因表达的关系依然知之甚少.本研究基于两个独立的6~14岁大样本儿童青少年静息态脑功能影像数据库,定量描绘了人脑功能网络的初级皮层-联合皮层连接梯度的发育轨迹.发现该连接梯度在儿童早期已经出现,并在8~11岁从次级梯度上升为首要核心梯度;其全局指标和局部分数都具有显著的年龄效应,梯度分数变化主要位于默认网络和感知觉皮层;梯度指标与个体工作记忆能力显著正相关,且连接梯度的发育受到脑功能网络分化与整合的中介调控.通过连接组-转录组联合分析,发现核心连接梯度的发育与突触传递等基因的表达水平显著相关.研究结果对理解人脑功能连接组的发育规则,建立脑发育性障碍的临床评估具有重要价值.

Connectome mapping studies have documented a principal primary-to-transmodal gradient in the adult brain network,capturing a functional spectrum that ranges from perception and action to abstract cognition.However,how this gradient pattern develops and whether its development is linked to cognitive growth,topological reorganization,and gene expression profiles remain largely unknown.Using longitudinal resting-state functional magnetic resonance imaging data from 305 children(aged 6-14 years),we describe substantial changes in the primary-to-transmodal gradient between childhood and adolescence,including emergence as the principal gradient,expansion of global topography,and focal tuning in primary and default-mode regions.These gradient changes are mediated by developmental changes in network integration and segregation,and are associated with abstract processing functions such as working memory and expression levels of calcium ion regulated exocytosis and synaptic transmission-related genes.Our findings have implications for understanding connectome maturation principles in normal development and developmental disorders.