Neuroscience
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In a bimanual task, proprioception provides information about position and movement of upper arms. Developmental studies showed improvement of proprioceptive accuracy and timing adjustments of muscular events from childhood to adulthood in bimanual tasks. However, the cortical maturational changes related to bimanual coordination is not fully understood. ⋯ Amplitude of the negative wave at C4 was higher in children and early adolescents compared to the other groups. In conclusion, we found a maturational process in cortical correlates related to motor planning and upper limb stabilization performance with interhemispheric lateralization appearing during adolescence. Findings may serve documenting bimanual performance in children with neurodevelopmental disorders.
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Resilience, a personality construct that reflects capacities to persevere, maintain a positive outlook and/or thrive despite ongoing stressors, has emerged as an important focus of research on chronic pain (CP). Although behavior studies have found more resilient persons with CP experience less pain-related dysfunction than less resilient cohorts do, the presence and nature of associated brain structure differences has received scant attention. To address this gap, we examined gray matter volume (GMV) differences between more versus less resilient adults with chronic musculoskeletal pain. ⋯ More (n = 57) and less (n = 61) resilient subgroups, respectively, were identified on the basis of scoring above and below median scores on two validated resilience questionnaires. Voxel-based morphology (VBM) undertaken to examine resilience subgroup differences in GMV indicated more resilient participants displayed significantly larger GMV in the (1) bilateral precuneus, (2) left superior and inferior parietal lobules, (3) orbital right middle frontal gyrus and medial right superior frontal gyrus, and (4) bilateral median cingulate and paracingulate gyri, even after controlling for subgroup differences on demographics and measures of pain-related distress. Together, results underscored the presence and nature of specific GMV differences underlying subjective reports of more versus less resilient responses to ongoing musculoskeletal pain.
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Working memory (WM) capacity, the amount of information one can hold online in mind, has a central role in cognition. Previous electrophysiological and imaging studies revealed the pivotal role of persistent activity within parietal and frontal regions as the neural foundations underpinning WM capacity. The best candidate molecules determining persistent activity are the brain's major excitatory and inhibitory neurotransmitters, glutamate and gamma-aminobutyric acid (GABA), respectively. ⋯ Individual variation in parieto-cingulate connectivity was explained by glutamatergic concentration in the IPS. Moreover, we found that parieto-cingulate connectivity mediated the relationship between interparietal sulcus glutamate and WM capacity. This set of findings reveals a novel mechanistic insight by which glutamatergic concentration within the IPS shapes WM capacity via parieto-cingulate connectivity.
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Alpha-synuclein (αS) is an intrinsically disordered protein (IDP) that is abundantly present in the brain and is associated with Parkinson's disease (PD). In spite of its abundance and its contribution to PD pathogenesis, the exact cellular function of αS remains largely unknown. The ability of αS to remodel phospholipid model membranes combined with biochemical and cellular studies suggests that αS is involved in endocytosis. ⋯ We find no structural colocalization between αS and clathrin and Rab11 positive vesicles. We conclude that in a physiological context, αS is structurally associated with caveolin dependent membrane vesiculation and is found further along the endocytic pathway, in decreasing amounts, on early and late endosomes. Our results not only shed new light on the function of αS, they also provide a possible link between αS function and vesicle trafficking malfunction in PD.