Measuring diffusion parameters in the brain: comparing the real-time iontophoretic method and diffusion-weighted magnetic resonance

Authors

  • I. Vorisek,

    1. Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, and Department of Neuroscience, Charles University, Prague, Czech Republic
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  • E. Sykova

    1. Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, and Department of Neuroscience, Charles University, Prague, Czech Republic
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E. Sykova, Department of Neuroscience, Institute of Experimental Medicine, ASCR, v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic. E-mail: sykova@biomed.cas.cz

Abstract

The extracellular space (ECS) diffusion parameters influence the movement of ions, neuroactive substances, hormones and metabolites in the nervous tissue. They also affect extrasynaptic transmission, a mode of signal transmission dependent solely on diffusion. This review compares in detail two methods for studying diffusion in the brain: the real-time iontophoretic tetramethylammonium method for ECS volume fraction and tortuosity measurements and diffusion weighted-magnetic resonance imaging for measuring the apparent diffusion coefficient of water. The results obtained using both methods under physiological conditions (post-natal development, ageing) or in pathologies (brain injury, ischaemia) and their similarities and differences are discussed.

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