Asymmetric signaling across the hierarchy of cytoarchitecture within the human connectome

Cortical variations in cytoarchitecture form a sensory-fugal axis that shapes regional profiles of extrinsic con-nectivity and is thought to guide signal propagation and integration across the cortical hierarchy. While neuro-imaging work has shown that this axis constrains local properties of the human connectome, it remains unclear whether it also shapes the asymmetric signaling that arises from higher-order topology. Here, we used network control theory to examine the amount of energy required to propagate dynamics across the sensory-fugal axis. Our results revealed an asymmetry in this energy, indicating that bottom-up transitions were easier to complete compared to top-down. Supporting analyses demonstrated that asymmetries were underpinned by a connec-tome topology that is wired to support efficient bottom-up signaling. Lastly, we found that asymmetries cor-related with differences in communicability and intrinsic neuronal time scales and lessened throughout youth. Our results show that cortical variation in cytoarchitecture may guide the formation of macroscopic connectome topology.

Automated summary

Cortical variations in cytoarchitecture may shape the sensory-fugal axis and influence brain connectivity and signal propagation. This study used network control theory to reveal an asymmetry in the energy required for bottom-up and top-down signal transmission, which was related to the connectome topology and decreased throughout youth.