Identifying non-toxic doses of manganese for manganese-enhanced magnetic resonance imaging to map brain areas activated by operant behavior in trained rats.

摘要: 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 a form of MnCl2, at dose 20mg/kg, was intraperitoneally infused. The administration repeated and separated by 24h to reach the 40mg/kg or 60mg/kg, respectively. Hepatotoxicity MnCl2 determining serum aspartate aminotransferase, alanine total bilirubin, albumin protein levels. Neurological examination also carried out. animals were tested visual cue discriminated task. Imaging performed using 3T clinical MR scanner. T1 values determined before after administrations. images each animal subtracted from their baseline calculate decrease value (ΔT1) voxel voxel. maps trained performing task, those naive rats compared. 60mg/kg showed hepatotoxic effect, even these did exhibit neurological symptoms. 20 increased number omissions affect accuracy Using accumulated 40mg/kg, voxels with significant enhanced ΔT1 detected following areas compared controls: visual, somatosensory, motor premotor cortices, insula, cingulate, ectorhinal, entorhinal, perirhinal piriform hippocampus, amygdala amygdalohippocampal areas, dorsal striatum, nucleus accumbens core, substantia nigra, retrorubral field. In conclusion, MEMRI proved be reliable method accomplish activity mapping correlation rodents.