Li Zhengjie, Liu Jiajun, Zheng Jianhui, Li Luying, Fu Ying, Yang Zhipeng
College of Electronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China.
Department of Radiology, Huaxi MR Research Center, West China Hospital, Sichuan University, Chengdu 610017, China.
Brain Sci. 2024 Dec 29;15(1):26. doi: 10.3390/brainsci15010026.
The spontaneous fluctuations in functional magnetic resonance imaging (fMRI) signals of the brain's gray matter (GM) have been interpreted as representations of neural activity variations. In previous research, white matter (WM) signals, often considered noise, have also been demonstrated to reflect characteristics of functional activity and interactions among different brain regions. Recently, functional gradients have gained significant attention due to their success in characterizing the functional organization of the whole brain. However, previous studies on brain functional gradients have predominantly focused on GM, neglecting valuable functional information within WM.
In this paper, we have elucidated the symmetrical nature of the functional hierarchy in the left and right brain hemispheres in healthy individuals, utilizing the principal functional gradient of the whole-brain WM while also accounting for gender differences.
Interestingly, both males and females exhibit a similar degree of asymmetry in their brain regions, albeit with distinct regional variations. Additionally, we have thoroughly examined and analyzed the distribution of functional gradient values in the spatial structure of the corpus callosum (CC) independently, revealing that a simple one-to-one correspondence between structure and function is absent. This phenomenon may be associated with the intricacy of their internal structural connectivity.
We suggest that the functional gradients within the WM regions offer a fresh perspective for investigating the structural and functional characteristics of WM and may provide insights into the regulation of neural activity between GM and WM.
大脑灰质（GM）的功能磁共振成像（fMRI）信号中的自发波动已被解释为神经活动变化的表现。在先前的研究中，通常被视为噪声的白质（WM）信号也已被证明能反映不同脑区的功能活动特征和相互作用。最近，功能梯度因其在表征全脑功能组织方面的成功而备受关注。然而，先前关于脑功能梯度的研究主要集中在灰质，忽略了白质内有价值的功能信息。
在本文中，我们利用全脑白质的主要功能梯度，并考虑性别差异，阐明了健康个体左右脑半球功能层次的对称性。
有趣的是，男性和女性在脑区都表现出相似程度的不对称性，尽管存在明显的区域差异。此外，我们独立地对胼胝体（CC）空间结构中的功能梯度值分布进行了全面检查和分析，发现结构与功能之间不存在简单的一一对应关系。这种现象可能与其内部结构连接的复杂性有关。
我们认为，白质区域内的功能梯度为研究白质的结构和功能特征提供了一个新的视角，并可能为深入了解灰质和白质之间的神经活动调节提供见解。
