<p>TMA<sup>+</sup>-diffusion curves with the corresponding values of the extracellular volume fraction (α), tortuosity (λ) and non-specific uptake (<i>k′</i>) obtained in the cortex of α-syn +/+ and α-syn −/− mice under resting conditions (<b>A, E</b>) as well as during acute cell swelling evoked by the application of hypotonic solutions H-50 (<b>B</b>), H-100 (<b>C</b>) or increased potassium (<b>D</b>) <i>in vitro</i> or by ischemia/anoxia <i>in vivo</i> (<b>F</b>). The values of the ECS diffusion parameters were determined by a non-linear curve fitting algorithm operating on the diffusion curve. The amplitude of the curves is inversely proportional to the ECS volume fraction while the shape of the curves reflects tortuosity.</p