Impact of manganese on the hippocampus metabolism in the context of MEMRI: a proton HRMAS MRS study
| Autor: | Sylvain Bohic, Emmanuel L. Barbier, Vasile Stupar, S. Maunoir-Regimbal, F. Fauvelle, Alexia Daoust |
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| Přispěvatelé: | Fédération Francophone de la Cancérologie Digestive, FFCD, European Synchrotron Radiation Facility (ESRF), Grenoble Institut des Neurosciences (GIN), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Biophysique Cellulaire et Moléculaire, Centre Recherche Service Santé Armée |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
inorganic chemicals
Chemistry Health Toxicology and Mutagenesis Metabolite Dentate gyrus Glutamate receptor Hippocampus Context (language use) Hippocampal formation Toxicology 030218 nuclear medicine & medical imaging 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Nuclear magnetic resonance In vivo [SDV.TOX]Life Sciences [q-bio]/Toxicology 030217 neurology & neurosurgery ComputingMilieux_MISCELLANEOUS Phosphocholine |
| Zdroj: | Toxicology Research Toxicology Research, Royal Society of Chemistry, 2015, 4 (2), pp.376-384. ⟨10.1039/c4tx00135d⟩ |
| ISSN: | 2045-452X 2045-4538 |
| DOI: | 10.1039/c4tx00135d⟩ |
| Popis: | Manganese enhanced MRI (MEMRI) offers many possibilities such as tract tracing of neuronal pathways and functional imaging in vivo. This technique necessitates a direct or indirect acute injection of MnCl2 in the brain. Unfortunately, local concentrations of Mn2+ and its impact on metabolism after a single injection remain largely unknown. In this study, we combined in vivo MEMRI and ex vivo Proton High Resolution Magic Angle Spinning MRS (1H HRMAS MRS) to investigate the delayed impact of Mn2+ on rat hippocampal metabolism. MEMRI images were acquired 24 h after MnCl2 injection in the dentate gyrus of the rat hippocampus at two different Mn2+ doses: low (8 nmol; n = 16) and high (500 nmol; n = 10). The low Mn2+ dose had almost no impact on hippocampal metabolism while the high dose altered the amplitude of several metabolites (up to +54% for Glu and −71% for Asp). Moreover, at this high dose, the paramagnetic properties of Mn2+ led to a broadening of the resonances of several organic acids (lactate, glutamate, N-acetyl aspartate etc.), suggesting a chelation of Mn2+ and an impact on Mn2+ relaxivity. Metabolite amplitudes were well correlated with the Mn2+ concentrations measured with an MRI T1-map (glutamate: R2 = 0.8, p = 0.02; phosphoethanolamine: R2 = 0.9, p = 0.0004; γ-aminobutyrate: R2 = 0.7, p = 0.005 and phosphocholine: R2 = 0.6, p = 0.04). To conclude, HRMAS is well suited to investigate Mn2+ impact on the metabolism. The low Mn2+ dose (8 nmol) usually used in the MEMRI experiment does not impact the hippocampal metabolism. The chelation of Mn2+ and its impact on relaxivity suggests an over-estimation of the Mn2+ concentration when measured through a T1 map. |
| Databáze: | OpenAIRE |
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