The highly complex structure of the brain is integral to its function, yet many aspects of the physical structure of the brain and how they aid its function remain poorly understood. Here we utilize millimeter-scale 3D reconstructions of brain volumes [1-3] to examine physical properties of the structure of the brain at the cellular level. Using techniques from statistical physics, we demonstrate that the physical structure of the brain displays features associated with structural criticality in physical systems, including long-range correlations and fractal properties. We show that the associated scaling exponents are consistent across the brains investigated, indicating potential structural universality in the brain.
 C. Shan Xu, et al., bioRxiv 2020.01.21.911859 (2020)
 MICrONs Consortium, et al., bioRxiv 2021.07.28.454025 (2021)
 A. Shapson-Coe, et al., bioRxiv 2021.05.29.446289 (2021)