Figure 5.

Modeling predicts slower propagation of spreading depression in AQP4^−/− mice. A. [K⁺]_e changes during the initial phase of CSD were modelled as described by Zandt et al. (Zandt et al. 2013) using experimentally determined values for K⁺ release rate (AQP4^+/+ 3.95 mM/s, AQP4^−/− 1.72 mM/s), reuptake rate constant (AQP4^+/+ 0.0226 s⁻¹, AQP4^−/− 0.0116 s⁻¹) and effective diffusion coefficient (AQP4^+/+ 0.796 × 10⁻⁵ cm²/s, AQP4^−/− 0.907 × 10⁻⁵ cm²/s). Neuronal K⁺ release threshold was set at 10 mM (dotted line). B. Dependence of CSD propagation velocity on rates of K⁺ release rate and removal modelled for a neuronal release threshold of 10 mM K⁺ and effective K⁺ diffusion coefficient of 2 × 10⁻⁵ cm²/s. Dotted lines denote experimentally measured release and removal rates in AQP4^+/+ and AQP4^−/− mice. C. Dependence of relative CSD propagation velocity on K⁺ diffusion coefficient and the threshold for neuronal K⁺ release.