Brain extracellular space as a diffusion barrier

Brain extracellular space as a diffusion barrier

The extracellular space (ECS) consists of the narrow channels between brain cells together with their geometrical configuration and contents. Despite being only 20-60 nm in width, the ECS typically occupies 20% of the brain volume. Numerous experiments over the last 50 years have established that molecules moving through the ECS obey the laws of diffusion but with an effective diffusion coeffic...

Diffusion in brain extracellular space.

Diffusion in the extracellular space (ECS) of the brain is constrained by the volume fraction and the tortuosity and a modified diffusion equation represents the transport behavior of many molecules in the brain. Deviations from the equation reveal loss of molecules across the blood-brain barrier, through cellular uptake, binding, or other mechanisms. Early diffusion measurements used radiolabe...

Modeling Ca2+ diffusion in brain extracellular space

Molecular diffusion in brain extracellular space (ECS) is primarily controlled by interactions with the geometry and the interstitial matrix. Both factors increase λ, the tortuosity, a measure of hindrance to diffusion where λ2 = D/D∗ with D the free diffusion coefficient and D∗ the effective diffusion coefficient in brain [1]. Geometry lengthens diffusion paths or creates holdup in local voids...

Modeling Brain Extracellular Space from Diffusion Data

The extracellular space (ECS) of the brain is a thin region surrounding each cell that is filled with a medium resembling cerebrospinal fluid and an unknown amount of extracellular matrix. The ECS is difficult to study but diffusion measurements based on a point-source diffusion paradigm have begun to reveal the complex structure of this region. Despite the complexity, a modified version of Fic...

Editorial: Brain Extracellular Space: Geometry, Matrix and Physiological Importance