NeuroImage
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We investigated the neural underpinnings of timbral, tonal, and rhythmic features of a naturalistic musical stimulus. Participants were scanned with functional Magnetic Resonance Imaging (fMRI) while listening to a stimulus with a rich musical structure, a modern tango. We correlated temporal evolutions of timbral, tonal, and rhythmic features of the stimulus, extracted using acoustic feature extraction procedures, with the fMRI time series. ⋯ While timbral feature processing was associated with activations in cognitive areas of the cerebellum, and sensory and default mode network cerebrocortical areas, musical pulse and tonality processing recruited cortical and subcortical cognitive, motor and emotion-related circuits. In sum, by combining neuroimaging, acoustic feature extraction and behavioral methods, we revealed the large-scale cognitive, motor and limbic brain circuitry dedicated to acoustic feature processing during listening to a naturalistic stimulus. In addition to these novel findings, our study has practical relevance as it provides a powerful means to localize neural processing of individual acoustical features, be it those of music, speech, or soundscapes, in ecological settings.
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Structural connectivity research in the human brain in vivo relies heavily on fiber tractography in diffusion-weighted MRI (DWI). The accurate mapping of white matter pathways would gain from images with a higher resolution than the typical ~2mm isotropic DWI voxel size. Recently, high field gradient echo MRI (GE) has attracted considerable attention for its detailed anatomical contrast even within the white and gray matter. ⋯ The STIFT method improves the anatomical accuracy of tractography of various fiber tracts, such as the optic radiation and cingulum. Furthermore, it has been demonstrated that STIFT can differentiate between kissing and crossing fiber configurations. Future investigations are required to establish the applicability in more white matter pathways.
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We argue that the emerging practice of using the author byline to acknowledge shared data is incompatible with current established standards for academic authorship. Non-author contributors, whether groups or individuals, should not be added to the author list of published papers. ⋯ Such dilution of authorship standards is problematic because it can compromise fair evaluations in the scientific community. We briefly discuss viable alternatives for crediting contributors, such as citations of papers describing shared data, reference to dataset publications, inclusion in the Acknowledgments section, or credit of individuals for sharing data in an Appendix, a solution that has been used in academic evaluation.
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Although the pathogenesis of amyotrophic lateral sclerosis (ALS) is uncertain, there is mounting neuroimaging evidence to suggest a mechanism involving the degeneration of multiple white matter (WM) motor and extramotor neural networks. This insight has been achieved, in part, by using MRI Diffusion Tensor Imaging (DTI) and the voxelwise analysis of anisotropy indices, along with DTI tractography to determine which specific motor pathways are involved with ALS pathology. Automated MRI structural connectivity analyses, which probe WM connections linking various functionally discrete cortical regions, have the potential to provide novel information about degenerative processes within multiple white matter (WM) pathways. ⋯ Maps of the outlier rejection voxels, revealed clusters within the corpus callosum and corticospinal projections. This finding highlights the importance of correcting for motion artefacts and physiological noise when studying clinical populations. Our novel findings, many of which are consistent with known pathology, show extensive involvement and degeneration of multiple corticomotor pathways in patients with upper and lower motor neuron signs and provide support for the use of automated structural connectivity techniques for studying neurodegenerative disease processes.
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Post-stroke microglial activation (MA) may have both neurotoxic and pro-repair effects, particularly in the salvaged penumbra. Mapping MA in vivo is therefore an important goal. 11C-PK11195, a ligand for the 18 kDa translocator protein, is the reference radioligand for MA imaging, but a correlation between the regional distributions of in vivo tracer binding and post mortem MA after stroke, as assessed with PET and immunohistochemistry, respectively, has not been demonstrated so far. Here we performed 11C-PK11195 microPET in a rat model previously shown to induce extensive cortical MA, and determined the correlation between 11C-PK11195 and immunostaining with the CD11 antibody OX42, so as to verify the presence of activated microglia, in a template of PET-resolution size regions-of-interest (ROIs) spanning the whole affected hemisphere. ⋯ The correlation between Day 14 11C-PK11195 and OX42 across the affected hemisphere from the same brain regions and animals further supports the validity of 11C-PK11195 as an in vivo imaging marker of MA following stroke. The finding of statistically significant increases in 11C-PK11195 as early as 48 h after stroke is novel. These results have implications for mapping MA after stroke, with potential therapeutic applications.