Functional changes of precuneus architecture across newborns, infants, and early adolescents.

Brain functional development from birth to adolescence follows the cortical gradient from primary sensorimotor to higher-order association regions. Precuneus (PCun) is crucial in spatial cognition, visual-motor integration, and social cognition. However, functional connectivity changes of PCun subregions in this dynamic developmental period are not known. Multimodal cross-sectional diffusion MRI and resting-state fMRI of subjects from birth to early adolescence were acquired to obtain structural and functional connectivity. PCun in neonates, 1-year-olds, 2-year-olds, and early adolescent subjects were consistently parcellated into four subregions based on structural connectivity of PCun. Significant developmental changes were found in functional connectivity between the parcellated PCun subregions and default mode network (DMN), and between the parcellated PCun subregions and cerebellum network. To understand altered development of PCun in brain disorders, connectivity-based parcellation was performed in the subjects with autism spectrum disorder (ASD). Similar parcellation pattern of PCun was found, but the relative volume of the dorsal-posterior subregion significantly decreased in the subjects with ASD compared to typically developmental subjects. These findings revealed functional developmental patterns of PCun subregions in their connected networks in typical developing brains and revealed PCun subregion alteration in ASD, shedding light onto functional changes of PCun architecture during development.