White matter functional gradients and their formation in adolescence

It is well known that functional magnetic resonance imaging (fMRI) is a widely used tool for studying brain activity. Recent research has shown that fluctuations in fMRI data can reflect functionally meaningful patterns of brain activity within the white matter. We leveraged resting-state fMRI from an adolescent population to characterize large-scale white matter functional gradients and their formation during adolescence. The white matter showed gray-matter-like unimodal-to-transmodal and sensorimotor-to-visual gradients with specific cognitive associations and a unique superficial-to-deep gradient with nonspecific cognitive associations. We propose two mechanisms for their formation in adolescence. One is a function-molded mechanism that may mediate the maturation of the transmodal white matter via the transmodal gray matter. The other is a structure-root mechanism that may support the mutual mediation roles of the unimodal and transmodal white matter maturation during adolescence. Thus, the spatial layout of the white matter functional gradients is in concert with the gray matter functional organization. The formation of the white matter functional gradients may be driven by brain anatomical wiring and functional needs.

Automated summary

It has been found that fluctuations in fMRI data can reflect meaningful patterns of brain activity in the white matter. This study used resting-state fMRI from adolescents to investigate the formation of large-scale white matter functional gradients. The results showed gray-matter-like unimodal-to-transmodal and sensorimotor-to-visual gradients with specific cognitive associations, as well as a unique superficial-to-deep gradient with nonspecific cognitive associations. The formation of these functional gradients is likely influenced by both functional and structural mechanisms during adolescence.