Development of functional connectivity gradients in multiple frequency bands

1255 

Abstract Submission 

Zhu-Qing Gong¹, Xi-Nian Zuo¹

¹Beijing Normal University, Beijing, China

Zhu-Qing Gong  
Beijing Normal University
Beijing, China

Xi-Nian Zuo  
Beijing Normal University
Beijing, China

A wide frequency range of brain oscillations can be recorded by various techniques. In the near century, a large number of electrophysiological studies have gradually accumulated evidence that oscillations in different frequencies are associated with different functions. In summary, high-frequency oscillations have more local connections and participate in bottom-up processes, while low-frequency oscillations have more long-distance connections and dominate in top-down processes (Buzsaki et al., 2004). In the past decade, an increasing number of functional magnetic resonance imaging (fMRI) studies have investigated the whole frequency range of blood oxygen level-dependent (BOLD) oscillations using multiband frequency analysis and found that BOLD oscillations have similar functional organization hierarchies in that different frequency bands dominate different functions (Zuo et al., 2010; Thompson et al., 2015; Gong et al., 2023). However, the multiband functional organization during development has not been revealed. In this study, we aimed to investigate the developmental patterns of functional organization in multiple frequency bands in school-aged children. Our hypothesis is that since the functions are different among frequency bands, the developmental processes would also differentiate among frequencies.

Resting-state fMRI data from 381 school-aged children from the Chinese Color Nest Project, an accelerated longitudinal dataset, were chosen for this research (Fan et al., 2023). The data were divided into different age groups from 6 to 18 years old, one for each year of age. After preprocessing, BOLD oscillations were decomposed into three frequency bands: slow-3 (0.082-0.200 Hz), slow-4 (0.031-0.082 Hz) and slow-5 (0.013-0.031 Hz). Then, we performed functional connectivity gradient analysis for each age group in all frequency bands. For each frequency band, spatial correlation of gradient distribution between every two age groups was conducted to quantify the phases and continuity of the developmental changes in gradient distribution patterns.

We mainly considered the first two gradients in this study since they account for the most variation. In each frequency band, the development of the two gradients throughout the school age can be divided into three stages (Fig. 1). In stage 1, the first gradient exhibited functional segmentation among primary sensory and motor regions; the second gradient exhibited functional integration from primary regions to associative regions. Stage 2 shows mixed transition modes for both gradients. In stage 3, the distribution pattern of the first and second gradients is reversed. Fig. 2 shows the developmental stages of the first and second gradients across different frequency bands. Overall, the first gradient maturated earlier than the second gradient, indicating that during the development of brain functional reorganization, functional segmentation is continuously optimized even after functional integration matures. The three frequency bands showed divergent developmental rates, as expected. For the first gradient, slow-3 matured the earliest, followed by slow-5 and then slow-4. For the second gradient, slow-5 matured the earliest, followed by slow-3 and finally slow-4. A recent study reported that slow-3, slow-4 and slow-5 are associated with sensory integration and language-related functions, executive functions, and self-related functions, respectively, offering an explanation for the current results that brain oscillations support these different functions having unique development courses (Gong et al., 2023).

Our study characterized the developmental patterns of BOLD oscillations in different frequency bands. The results revealed that the development of brain function is both phased and continuous. The divergent developmental courses for different frequency bands provide evidence for the frequency specificity of brain function.

Early life, Adolescence, Aging ¹

Connectivity (eg. functional, effective, structural)

BOLD fMRI ²

Development

FUNCTIONAL MRI

Other - multiple frequency bands; oscillations