Dependence of the Extra‐Cellular Diffusion Coefficient on the Fractions of Neurites and Cell Bodies in Gray Matter
Hong‐Hsi Lee, Ali Abdollahzadeh, Hansol Lee, Ricardo Coronado‐Leija, Els Fieremans, Susie Y. Huang, Dmitry S. Novikov · 2026
Read Dependence of the Extra‐Cellular Diffusion Coefficient on the Fractions of Neurites and Cell Bodies in Gray Matter by Hong‐Hsi Lee, Ali Abdollahzadeh, Hansol Lee, Ricardo Coronado‐Leija, Els Fieremans, Susie Y. Huang, Dmitry S. Novikov (2026) in the Tower of Babel, a free online library of public-domain works preserved in clean, searchable text. No sign-up. The full text is served as a plain-text file at a predictable URL, where text is present: https://antarctic-labs.com/tower-of-babel/PMC13527277.txt.
Description
Hong-Hsi Lee and colleagues derive, in a 2026 theory and simulation study, how water diffusion outside brain cells depends on the mix of cell bodies and neurites in gray matter. Diffusion MRI infers tissue microstructure from water movement, and the long-time limit of outside-cell diffusion anchors such models. White matter relations were known, while gray matter's mixed geometry blocked a formula.
Borrowing effective medium theory from nineteenth-century conductivity problems, the team coarse-grained tissue as spheres for cell bodies and cylinders for neurites embedded in a matrix. Closed-form expressions gave power-law scaling of outside-cell diffusivity with the volumes of the spaces around each element. Monte Carlo simulations and realistic tissue geometries corroborated the formulas, and in vivo MRI data were fitted as a demonstration. A protocol for measuring cell body size follows.
Catalog record
| CREATOR | Hong‐Hsi Lee, Ali Abdollahzadeh, Hansol Lee, Ricardo Coronado‐Leija, Els Fieremans, Susie Y. Huang, Dmitry S. Novikov |
|---|---|
| YEAR | 2026 |
| COLLECTION | PAPERS |
| FORMAT | TXT |
| FILE SIZE | 49349 |
| LICENSE | https://creativecommons.org/licenses/by/4.0 |
| RIGHTS | CC BY |
| SOURCE | Europe PMC |