Chapter

Biophysics of Diffusion in Cells

Joseph J.H. Ackerman and Jeffrey J. Neil

in Diffusion MRI

Published on behalf of Oxford University Press

Published in print November 2010 | ISBN: 9780195369779
Published online September 2012 | e-ISBN: 9780199965144 | DOI: http://dx.doi.org/10.1093/med/9780195369779.003.0008
Biophysics of Diffusion in Cells

More Like This

Show all results sharing this subject:

  • Neuroscientific Techniques

GO

Show Summary Details

Preview

Measurements of intracellular water diffusion in living tissue and quantitative interpretation of diffusion data are challenged by a number of things: the effects of a generally chaotic microstructure that presents numerous hindrances and restrictions to displacement over a range of length scales; the contribution of both intracellular and extracellular water to the diffusion signal; and the exchange of water between these spaces. One consequence of this complexity is that the MR diffusion signal attenuation curve for tissue water is not well modeled using a simple monoexponential function as would be expected for free (unhindered/unrestricted) diffusion. The non-monoexponential diffusion signal likely reflects a distribution of tissue water displacement properties rather than distinct water populations or compartments. Specialized measurements of diffusion in isolated cell systems and rodent models provide evidence that the apparent free intracellular diffusion coefficient is one-half to two-thirds that of a dilute aqueous solution (i.e., ~1.5 to 2 μm2P/ms). Evaluation of the decrease in tissue water apparent diffusion coefficient accompanying water brain injury suggests that this change is largely related to a decrease in the diffusion of intracellular water, though other factors likely play a role as well.

Chapter.  12336 words.  Illustrated.

Subjects: Neuroscientific Techniques

Full text: subscription required

How to subscribe Recommend to my Librarian

Buy this work at Oxford University Press »

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.