Myelin development in visual scene-network tracts beyond late childhood: A multimethod neuroimaging study

The visual scene-networkdcomprising the parahippocampal place area (PPA), retrosplenial cortex (RSC), and occipital place area (OPA)dshows a prolonged functional development. Structural development of white matter that underlies the scene-network has not been investigated despite its potential influence on scene-network function. The key factor for white matter maturation is myelination. However, research on myelination using the gold standard method of post-mortem histology is scarce. In vivo alternatives diffusion-weighted imaging (DWI) and myelin water imaging (MWI) so far report broad scale findings that prohibit inferences concerning the scene-network. Here, we combine MWI, DWI tractography, and fMRI to investigate myelination in scene-network tracts in middle childhood, late childhood, and adulthood. We report increasing myelin from middle childhood to adulthood in right PPA-OPA, and trends towards increases in the left and right RSC-OPA tracts. Investigating tracts to regions highly connected with the scene-network, such as early visual cortex and the hippocampus, did not yield any significant age group differences. Our findings indicate that structural development coincides with functional development in the scene-network, possibly enabling structureefunction interactions. ? 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study investigated myelination in scene-network tracts using a combination of MWI, DWI tractography, and fMRI in middle childhood, late childhood, and adulthood. The findings show increasing myelin in the right PPA-OPA tract from middle childhood to adulthood, with trends towards increases in the left and right RSC-OPA tracts.