Neuroscience
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Thalamocortical dysfunction is thought to underlie the pathophysiology of chronic pain revealed by electroencephalographic studies. The thalamus serves as a primary relay center to transmit sensory information and motor impulses via dense connections with the somatosensory and motor cortex. In this study, diffusion tensor imaging (DTI) (probabilistic tractography) and resting-state functional magnetic resonance imaging (functional connectivity) were used to characterize the anatomical and functional integrity of the thalamo-sensorimotor pathway in chronic low back pain (cLBP). ⋯ Moreover, there was significantly altered resting-state functional connectivity (rsFC) of bilateral thalamo-motor/somatosensory pathways in patients with cLBP as compared to healthy controls. We also detected a significant correlation between pain intensity during the MRI scan and rsFC of the right thalamo-somatosensory pathway in cLBP. Our findings highlight the involvement of the thalamo-sensorimotor circuit in the pathophysiology of cLBP.
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Although altered microstructure properties of white-matter tracts have been reported in children with attention-deficit/hyperactivity disorder (ADHD), findings from relatively few adult ADHD studies are inconsistent. This study aims to examine microstructural property over the whole brain in adults with ADHD and explore structural connectivities. Sixty-four medication-naïve adults with ADHD and 81 healthy adults received diffusion spectrum imaging. ⋯ Adults with ADHD had increased mGFA values in the segments located in the left frontal aslant tract, the right inferior longitudinal fasciculus, and the left perpendicular fasciculus, and reduced mGFA values in the segments located in the right superior longitudinal fasciculus (SLF) I, the left SLF II, the right frontostriatal tracts from dorsolateral prefrontal cortex and the ventrolateral prefrontal cortex, the right medial lemniscus, the right inferior thalamic radiation to the auditory cortex, and the callosal fibers. Additionally, the mGFA value of the right SLF I segment was associated with hyperactivity-impulsivity symptoms. Our findings suggest that white-matter tracts with altered microstructure properties are located within the attention networks, fronto-striato-thalamocortical regions, and those associated with attention and visual perception in adults with ADHD.
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A growing number of functional neuroimaging studies have identified regions within the temporal lobe, particularly along the planum polare and planum temporale, that respond more strongly to music than other types of acoustic stimuli, including voice. This "music preferred" regions have been reported using a variety of stimulus sets, paradigms and analysis approaches and their consistency across studies confirmed through meta-analyses. However, the critical question of intra-subject reliability of these responses has received less attention. ⋯ Results demonstrated that music-preferred activity previously reported in temporal regions, and its modulation by expertise, exhibits a high intra-subject reliability. However, we also found that activity in some extra-temporal regions, such as the precentral and middle frontal gyri, did depend on the particular stimuli employed, which may explain why these are less consistently reported in the literature. Taken together, our findings confirm and extend the notion that specific regions in the brain consistently respond more strongly to certain socially-relevant stimulus categories, such as faces, voices and music, but that some of these responses appear to depend, at least to some extent, on the specific features of the paradigm employed.
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The Munc13 family of proteins is critically involved in synaptic vesicle priming and release in glutamatergic neurons in the brain. Munc13-1 binds to alcohol and, in Drosophila, modulates sedation sensitivity and self-administration. We examined the effect of alcohol consumption on the expression of Munc13-1 and Munc13-2, NMDA receptor subunits GluN1, GluN2A and GluN2B in the hippocampus-derived HT22 cells, hippocampal primary neuron culture, and wild-type and Munc13-1+/- male mouse hippocampus after ethanol consumption (Drinking in the Dark (DID) paradigm). ⋯ The NMDA receptor subunits, GluN1, GluN2A and GluN2B were upregulated in the hippocampal primary culture and in the CA1. Ethanol exerts a differential effect on the expression of Munc13-1 and Munc13-2 in the CA1 in male mice. Our study also found that ethanol's effect on Munc13 expression is dependent on the experimental paradigm, and both Munc13-1 and Munc13-2 could contribute to the ethanol-induced augmentation of glutamatergic neurotransmission.