Perez Karla, Allen Ahmad, Tyagi Christina, Tung Sarah S, Fascendini Bella, Yan Xiaoqian, Horenziak Juliet, Ortiz Danya, Wu Hua, Grill-Spector Kalanit, Natu Vaidehi S
Department of Psychology, Stanford University, Stanford, CA, 94305, USA.
Department of Psychology, Princeton University, Princeton, NJ, 08544, USA.
bioRxiv. 2025 Jun 22:2025.06.20.660718. doi: 10.1101/2025.06.20.660718.
Development of gray and white matter tissue microstructure is critical for the emergence of sensory and cognitive functions. However, it is unknown how microstructural tissue properties of the human visual system develop in the first year of human life. Here, we use tissue relaxation rate ( ) obtained using quantitative MRI to measure the longitudinal development of gray and white matter in brain areas spanning three visual processing streams: dorsal, lateral, and ventral, during the first year of life. in gray and white matter of all visual regions in the three processing streams increases postnatally, indicating microstructural tissue growth. increases faster between 0-6 months than 6-12 months, and faster in white matter than gray matter, with white matter surpassing that of gray matter after two months of age. Strikingly, this microstructural growth is hierarchical: across all streams, early visual areas are more mature at birth than higher-level areas but develop more slowly postnatally than higher-level areas. The exception is TO1 (MT) which is similar to V1: it is microstructurally more mature at birth and develops slower than neighboring areas. Overall, our findings provide the first comprehensive measurement of microstructural tissue growth in infancy across three visual processing streams and propose a new hypothesis that functional development of the visual cortex may be coupled with microstructural development and follows a similar hierarchical trajectory.
灰质和白质组织微观结构的发育对于感觉和认知功能的出现至关重要。然而，人类视觉系统的微观结构组织特性在生命的第一年如何发育尚不清楚。在此，我们使用通过定量MRI获得的组织弛豫率（ ）来测量生命第一年中跨越三个视觉处理流（背侧、外侧和腹侧）的脑区中灰质和白质的纵向发育。三个处理流中所有视觉区域的灰质和白质中的 在出生后增加，表明组织微观结构生长。在0 - 6个月之间比6 - 12个月增加得更快，并且在白质中比灰质增加得更快，白质中的 在两个月大后超过灰质。引人注目的是，这种微观结构生长是分层的：在所有流中，早期视觉区域在出生时比高级区域更成熟，但在出生后比高级区域发育得更慢。例外的是TO1（MT），它与V1相似：它在出生时微观结构上更成熟，并且比相邻区域发育得更慢。总体而言，我们的研究结果首次全面测量了婴儿期三个视觉处理流中的组织微观结构生长，并提出了一个新的假设，即视觉皮层的功能发育可能与微观结构发育相关联，并遵循类似的分层轨迹。
