Multiphasic myelination and dendritic growth modulate qMRI signals in human visual cortex
Year: 2026
Type: preprint
Abstract: How does myelin develop in human visual cortex? By combining immunohistochemistry with in vivo and postmortem magnetic resonance imaging of longitudinal relaxation rate (R 1 ), which increases with myelin content, we find that myelin and R 1 increase across development but follow distinct trajectories. Immunohistochemistry reveals two phases of myelination: an infant phase of limited oligodendrogenesis, with myelin restricted to deep cortical layers, followed by widespread myelination across all layers during childhood. Cortical R 1 also increases across development and correlates with myelin by childhood. However, in infancy, R 1 increases outpace myelin growth and instead tracks dendritic arborization, indicating that the microstructural drivers of R 1 change across development. We hypothesize that deep layer myelination in infancy contributes to early visual function whereas later myelination of superficial layers enables prolonged cortical plasticity and learning of complex visual behaviors.
Authors: Clara María Bacmeister, Vaidehi S. Natu, Alex Rezai, Sarah Tung, Christina Tyagi, Xiaoqian Yan, Kei Braun, Michael Mui, Congyu Liao, Nan Wang, Xiaozhi Cao, Hua Wu, Patrik Johansson, Annika Enejder, Alexander Beckett, Erica Walker, David Feinberg, Kawin Setsompop, Mercedes Paredes, Kalanit Grill-Spector
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: Neuroimaging and histological investigations of human visual cortex development, Robust and precise imaging of infant brain development with magnetic resonance imaging, Integrate neuroimaging, molecular quantitation, and cytoarchitecture to elucidate the development of myelination in human visual cortex., Visual Cortex as a Window to Microstructural and Functional Development of the Human Brain, Next generation in-vivo diffusion imaging at submillimeter resolution
OpenAlex ID: W7160060072