The regulation of emotion is vital for adaptive behavior in a social environment. Different strategies may be adopted to achieve successful emotion regulation, ranging from attentional control (e.g., distraction) to cognitive change (e.g., reappraisal). However, there is only scarce evidence comparing the different regulation strategies with respect to their neural mechanisms and their effects on emotional experience. We, therefore, directly compared reappraisal and distraction in a functional magnetic resonance imaging study with emotional pictures. In the distraction condition participants performed an arithmetic task, while they reinterpreted the emotional situation during reappraisal to downregulate emotional intensity. Both strategies were successful in reducing subjective emotional state ratings and lowered activity in the bilateral amygdala. Direct contrasts, however, showed a stronger decrease in amygdala activity for distraction when compared with reappraisal. While both strategies relied on common control areas in the medial and dorsolateral prefrontal and inferior parietal cortex, the orbitofrontal cortex was selectively activated for reappraisal. In contrast, the dorsal anterior cingulate and large clusters in the parietal cortex were active in the distraction condition. Functional connectivity patterns of the amygdala activation confirmed the roles of these specific activations for the 2 emotion regulation strategies.
23 Na MRI has the potential to noninvasively detect sodium (Na) content changes in vivo. The goal of this study was to implement 23 Na MRI in a clinical setting for neurooncological and muscular imaging. Due to the biexponential T 2 decay of the tissue Na signal with a short component, which ranges between 0.5-8 ms, the measurement of total Na content requires imaging techniques with echo times (TEs) below 0.5 ms. A 3D radial pulse sequence with a TE of 0.2 ms at a spatial resolution of 4 ؋ 4 ؋ 4 mm 3 was developed that allows the acquisition and presentation of Na images on the scanner. This sequence was evaluated in patients with low-and high-grade gliomas, and higher 23 Na MR signals corresponding to an increased Na content were found in the tumor regions. The contrast-to-noise ratio (CNR) between tumor and white matter increased from 0.8 ؎ 0.2 to 1.3 ؎ 0.3 with tumor grade. In patients with an identified muscular 23 Na channelopathy (Paramyotonia congenita (PC)), induced muscle weakness led to a signal increase of ϳ18% in the 23 Na MR images, which was attributed to intracellular Na ؉ accumulation in this region. Magn Reson Med 57: 74 -81, 2007.
Our data implicate MPO in atherosclerotic plaque instability and suggest that non-invasive imaging and pharmacological inhibition of plaque MPO activity hold promise for clinical translation in the management of high-risk coronary artery disease.
The nuclear transactive response DNA-binding protein 43 (TDP-43) undergoes relocalization to the cytoplasm with formation of cytoplasmic deposits in neurons in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Pathogenic mutations in the TDP-43-encoding TARDBP gene in familial ALS as well as non-mutant human TDP-43 have been utilized to model FTD/ALS in cell culture and animals, including mice. Here, we report novel A315T mutant TDP-43 transgenic mice, iTDP-43(A315T), with controlled neuronal over-expression. Constitutive expression of human TDP-43(A315T) resulted in pronounced early-onset and progressive neurodegeneration, which was associated with compromised motor performance, spatial memory and disinhibition. Muscle atrophy resulted in reduced grip strength. Cortical degeneration presented with pronounced astrocyte activation. Using differential protein extraction from iTDP-43(A315T) brains, we found cytoplasmic localization, fragmentation, phosphorylation and ubiquitination and insolubility of TDP-43. Surprisingly, suppression of human TDP-43(A315T) expression in mice with overt neurodegeneration for only 1 week was sufficient to significantly improve motor and behavioral deficits, and reduce astrogliosis. Our data suggest that functional deficits in iTDP-43(A315T) mice are at least in part a direct and transient effect of the presence of TDP-43(A315T). Furthermore, it illustrates the compensatory capacity of compromised neurons once transgenic TDP-43 is removed, with implications for future treatments.
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