The spatial organization of ascending auditory pathway microstructural maturation from infancy through adolescence using a novel fiber tracking approach

Auditory perception is established through experience-dependent stimuli exposure during sensitive developmental periods; however, little is known regarding the structural development of the central auditory pathway in humans. The present study characterized the regional developmental trajectories of the ascending auditory pathway from the brainstem to the auditory cortex from infancy through adolescence using a novel diffusion MRI-based tractography approach and along-tract analyses. We used diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) to quantify the magnitude and timing of auditory pathway microstructural maturation. We found spatially varying patterns of white matter maturation along the length of the tract, with inferior brainstem regions developing earlier than thalamocortical projections and left hemisphere tracts developing earlier than the right. These results help to characterize the processes that give rise to functional auditory processing and may provide a baseline for detecting abnormal development. HighlightsO_LIWe characterize the microstructural maturation of the auditory pathway C_LIO_LIWe show structural development of the auditory pathway is dynamic and heterogeneous C_LIO_LIDiffusion metrics AD, RD and MD reach adult-like levels earlier than FA and NDI C_LIO_LIBrainstem microstructure matures earlier than the subcortical white matter C_LIO_LIMaturation of the right auditory pathway continues later than the left C_LI