Extracellular space diffusion in central nervous system: anisotropic diffusion measured by elliptical surface photobleaching.

ABSTRACT: Diffusion in the extracellular space (ECS) is crucial for normal central nervous system physiology. The determinants of ECS diffusion include viscous interactions with extracellular matrix/plasma membranes ("viscosity") and ECS geometry ("tortuosity"). To resolve viscosity versus tortuosity effects, we measured direction-dependent (anisotropic) diffusion in ECS in mouse spinal cord by photobleaching using an elliptical spot produced by a cylindrical lens in the excitation path. Anisotropic diffusion slowed fluorescence recovery when the long axis of the ellipse was parallel versus perpendicular to the direction of faster diffusion. A mathematical model was constructed to deduce diffusion coefficients (D(x), D(y)) from fluorescence recovery measured for parallel and perpendicular orientatio

SUBMITTER: Papadopoulos MC 

PROVIDER: S-EPMC1366858 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature