Fig. 3. Concentration dependence and the calcium addition effect on transcranial manganese delivery efficiency.

R₁-maps calculated from saturation recovery MR images of rats receiving - (A) 100 mM MnCl₂ (slice shown is approximately 1.5 mm anterior from bregma), (B) 100 mM MnCl₂+400 mM CaCl₂ (slice is approximately −0.6 mm posterior from bregma), (C) 250 mM MnCl₂ (slice shown is approximately −0.5 mm posterior from bregma) and (D) 300 mM MnCl₂+200 mM CaCl₂ (slice shown is approximately −0.6 mm posterior from bregma) on the bregma and dependence of total amount of manganese delivered to the brain on the concentration of manganese solution applied on the bregma, when only MnCl₂ was applied (red diamonds) and when CaCl₂ was added to the total concentration of 500 mM (blue squares) (E). Scale bar, 2 mm. R₁ intensity scaling, 0.125–1 s⁻¹. ROIs where T₁ measurements were made are shown on the top of the R₁ maps in red or blue, whereas the green ROIs represent the background. Ca²⁺ increases the efficiency of Mn²⁺ delivery through the skull. Each data point represents the average of three animals.