RETINOTOPIC ORGANIZATION OF CONNECTOME AND CELL-TYPE COMPOSITION IN PRIMATE EARLY VISUAL CORTEX

Understanding how the brain represents visual space requires moving beyond traditional anatomical parcellations toward frameworks that capture fine-scale structural and functional variations. We frame spatial patterning—the systematic organization of neural features across cortical space — as a core principle underlying the specialized retinotopic architecture of the visual system, encompassing systematic biases between central and peripheral vision as well as upper and lower visual fields. Large-scale spatial transcriptomic data in macaque cortex reveal gradients of cell‑type composition and gene expression that correlate with both functional hierarchy and regional cortical topography, providing a molecular context for spatial organization across the cortex.
In this project, we propose an integrative framework to characterize fine‑scale structural and molecular variation across retinotopic subdivisions of visual cortex. We found distinct connectivity profiles shaped by eccentricity — including log FLN measures and SLN-based hierarchical distances — across hierarchical levels in early visual areas. Upper visual field representations receive stronger projections from ventral stream pathways, whereas lower field representations exhibit stronger dorsal stream inputs supported by a profound distance rule. Hierarchical distance across V1-V2-V4-MT exhibits a certain degree of inconsistency across different eccentricities.
Underlying the anatomical connectivity, the spatial transcriptomic analysis revealed molecular signatures varying across eccentricities, hierarchical levels, and cortical layers in early visual areas, yielding a molecular basis for connectivity heterogeneity. By framing retinotopic subdivisions as fundamental units of anatomical, hierarchical, and molecular variation, this work advances a multiscale understanding of visual cortical organization and provides new insights into how the primate brain encodes retinotopic information.