caa a22 4500 606202102 CHVBK 20210128100951.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00429-014-0742-8 doi (NATIONALLICENCE)springer-10.1007/s00429-014-0742-8 Reduced intracellular mobility underlies manganese relaxivity in mouse brain in vivo: MRI at 2.35 and 9.4T [Elektronische Daten] [Takashi Watanabe, Jens Frahm, Thomas Michaelis] Using T 1-weighted MRI at two different magnetic field strengths, the enhanced longitudinal relaxivity due to paramagnetic manganese ions in mouse brain in vivo is shown to reflect reduced intracellular mobility. One day after systemic administration of manganese chloride, increases of the longitudinal relaxation rate ∆R 1 in several brain regions are significantly higher at 2.35T than at 9.4T. The corresponding relaxivity ratios 100 r 1/400 r 1=100∆R 1/400∆R 1 range from 2.4 (striatum) to 4.4 (cerebellar cortex). In contrast, the ∆R 1 values after intraventricular administration of gadolinium-DTPA (Gd-DTPA) are not significantly different between both field strengths yielding 100 r 1/400 r 1 ratios from 1.0 to 1.1. The same observation holds true for manganese and Gd-DTPA relaxivities in aqueous solution. The pronounced field strength dependence of manganese relaxivities indicates a reduced mobility of manganese ions in vivo by confinement to a viscous fluid compartment and/or due to macromolecular binding. Moreover, preferential enhancement of nerve cell assemblies by manganese ions and the observation of additional contrast enhancement by magnetization transfer suggest an intracellular localization of manganese. This is further supported by a slow release of manganese from nerve cells postmortem, which occurs despite a high permeability of damaged cellular membranes as demonstrated by a rapid uptake of extracellular Gd-DTPA. Springer-Verlag Berlin Heidelberg, 2014 Brain mapping nationallicence Contrast media nationallicence Gadolinium-DTPA nationallicence Intraventricular injections nationallicence Manganese chloride nationallicence Subcutaneous injections nationallicence Watanabe Takashi Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für Biophysikalische Chemie, 37070, Göttingen, Germany aut Frahm Jens Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für Biophysikalische Chemie, 37070, Göttingen, Germany aut Michaelis Thomas Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für Biophysikalische Chemie, 37070, Göttingen, Germany aut Brain Structure and Function Springer Berlin Heidelberg 220/3(2015-05-01), 1529-1538 1863-2653 220:3<1529 2015 220 429 https://doi.org/10.1007/s00429-014-0742-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00429-014-0742-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Watanabe Takashi Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für Biophysikalische Chemie, 37070, Göttingen, Germany aut NATIONALLICENCE 700 1- Frahm Jens Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für Biophysikalische Chemie, 37070, Göttingen, Germany aut NATIONALLICENCE 700 1- Michaelis Thomas Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für Biophysikalische Chemie, 37070, Göttingen, Germany aut NATIONALLICENCE 773 0- Brain Structure and Function Springer Berlin Heidelberg 220/3(2015-05-01), 1529-1538 1863-2653 220:3<1529 2015 220 429