@article{MTMT:3148677, title = {Identifying non-toxic doses of manganese for manganese-enhanced magnetic resonance imaging to map brain areas activated by operant behavior in trained rats.}, url = {https://m2.mtmt.hu/api/publication/3148677}, author = {Gálosi, Rita and Szalay, László Csaba and Aradi, Mihály and Perlaki, Gábor and Pál, József and Steier, Roy and Lénárd, László and Karádi, Zoltán György}, doi = {10.1016/j.mri.2016.11.017}, journal-iso = {MAGN RESON IMAGING}, journal = {MAGNETIC RESONANCE IMAGING}, volume = {37}, unique-id = {3148677}, issn = {0730-725X}, abstract = {Manganese-enhanced magnetic resonance imaging (MEMRI) offers unique advantages such as studying brain activation in freely moving rats, but its usefulness has not been previously evaluated during operant behavior training. Manganese in a form of MnCl2, at a dose of 20mg/kg, was intraperitoneally infused. The administration was repeated and separated by 24h to reach the dose of 40mg/kg or 60mg/kg, respectively. Hepatotoxicity of the MnCl2 was evaluated by determining serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, albumin and protein levels. Neurological examination was also carried out. The animals were tested in visual cue discriminated operant task. Imaging was performed using a 3T clinical MR scanner. T1 values were determined before and after MnCl2 administrations. Manganese-enhanced images of each animal were subtracted from their baseline images to calculate decrease in the T1 value (DeltaT1) voxel by voxel. The subtracted T1 maps of trained animals performing visual cue discriminated operant task, and those of naive rats were compared. The dose of 60mg/kg MnCl2 showed hepatotoxic effect, but even these animals did not exhibit neurological symptoms. The dose of 20 and 40mg/kg MnCl2 increased the number of omissions and did not affect the accuracy of performing the visual cue discriminated operant task. Using the accumulated dose of 40mg/kg, voxels with a significant enhanced DeltaT1 value were detected in the following brain areas of the visual cue discriminated operant behavior performed animals compared to those in the controls: the visual, somatosensory, motor and premotor cortices, the insula, cingulate, ectorhinal, entorhinal, perirhinal and piriform cortices, hippocampus, amygdala with amygdalohippocampal areas, dorsal striatum, nucleus accumbens core, substantia nigra, and retrorubral field. In conclusion, the MEMRI proved to be a reliable method to accomplish brain activity mapping in correlation with the operant behavior of freely moving rodents.}, year = {2017}, eissn = {1873-5894}, pages = {122-133} } @article{MTMT:2822625, title = {Monitoring of Short-Term Erythropoietin Therapy in Rats with Acute Spinal Cord Injury Using Manganese-Enhanced Magnetic Resonance Imaging}, url = {https://m2.mtmt.hu/api/publication/2822625}, author = {Freitag, MT and Márton, Gábor and Pajer, Krisztián and Hartmann, J and Walder, N and Rossmann, M and Parzer, P and Redl, H and Nógrádi, Antal and Stieltjes, B}, doi = {10.1111/jon.12202}, journal-iso = {J NEUROIMAGING}, journal = {JOURNAL OF NEUROIMAGING}, volume = {25}, unique-id = {2822625}, issn = {1051-2284}, abstract = {BACKGROUND AND PURPOSE: To evaluate the short-term outcome of erythropoietin (EPO) therapy in rats with spinal cord injury (SCI) using manganese-enhanced magnetic resonance imaging (MEMRI). METHODS: Rats were divided in an EPO and a control group. Laminectomy at Th11 was performed, followed by SCI. MnCl2 was applied into the cisterna magna and functional recovery was examined after injury using BBB-scoring. Then, rats were euthanized and the spinal cord was extracted for MEMRI. Finally, histological analysis was performed and correlated with MEMRI. RESULTS: EPO-treated animals showed significantly better functional recovery (P = .008, r = .62) and higher mean signal-to-noise ratio (SNR) in MEMRI compared to controls for slices 10-13 (P = .017, R2 = .31) at the level of the lesion epicenter. Functional recovery correlated significantly with higher SNR values, determined using the mean SNR between slices 10 and 13 (P = .047, R2 = .36). In this region, histology revealed a significantly decreased number of microglia cells and apoptosis in EPO-treated animals. CONCLUSION: MEMRI successfully depicts the therapeutic effect of EPO in early SCI that leads to a significant recovery in rats, a significantly reduced immune response and significantly reduced number of apoptotic cells at the height of the lesion epicenter.}, year = {2015}, eissn = {1552-6569}, pages = {582-589} }