Neuroscience
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Motor feedback usually engages distinct sensory and cognitive processes based on different feedback conditions, e.g., the real and sham feedbacks. It was thought that these processes may rely on the functional connectivity among the brain networks. However, it remains unclear whether there is a difference in the network connectivity between the two feedback conditions. ⋯ Using independent component analysis and functional connectivity analysis, we found that as compared with the sham feedback, the real feedback recruited stronger negative connectivity between the executive network (EN) and the posterior default mode network (pDMN). More intriguingly, the left frontal parietal network (lFPN) exhibits positive connectivity with the pDMN in the real feedback while in the sham feedback, the lFPN shows connectivity with the EN. These results suggest that the connectivity among EN, pDMN, lFPN could differ depending on the real and sham feedbacks, and the lFPN may balance the competition between the pDMN and EN, thus supporting the sensory and cognitive processes of the motor feedback.
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Our working hypothesis is that brain neurotrophins and brain Na(+),K(+)-ATPase may be strongly associated with the occurrence of depression in animals subjected to chronic unpredictable mild stress (CUMS). Still, we believe that chrysin, a natural and bioactive flavonoid found in honey and some plants, can provide satisfactory effects on antidepressant therapy. Thus, we aimed to evaluate the effect of CUMS on brain-derived neurotropic factor (BDNF) and nerve growth factor (NGF) levels as well as the Na(+),K(+)-ATPase activity in the hippocampus and prefrontal cortex of female mice. ⋯ In conclusion, CUMS decreased BDNF and NGF levels as well as the Na(+),K(+)-ATPase activity in mice. Chrysin presented antidepressant effect in mice on behavioral, neurotrophic and biochemistry parameters equivalent to fluoxetine. Furthermore, we suggest that the up-regulation of BDNF and NGF levels is a mechanism possibly involved in the antidepressant effect of chrysin in mice.
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Diabetes mellitus (DM) is a major risk factor for stroke and it exacerbates tissue damage after ischemic insult. Diabetes is one of the important causes of the progression of white matter lesion, however, the pathological mechanisms remain unclear. The present study evaluated the influences of type 2 DM on ischemic subcortical white matter injury and the recruitment of oligodendrocyte progenitor cells (OPCs) under chronic cerebral hypoperfusion using type 2 diabetic (db/db) mice. ⋯ Finally, we assessed the survival of 5-bromo-2'-deoxyuridine (BrdU)-positive proliferating cells in ischemic white matter, and found significantly poorer survival of BrdU/PDGFRα-positive OPCs or BrdU/GST-pi-positive OLGs in the db/db mice compared to the db/+ mice in the white matter after BCAS. Our findings suggest that the type 2 DM mice exhibited more severe white matter injury 8 weeks after chronic ischemia. Decreased proliferation and survival of OPCs may play an important role in the progression of white matter lesions after ischemia in diabetics.
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Both central and peripheral sympathetic nervous systems contribute to the cardiovascular effects of dexmedetomidine (DMED), a highly selective and widely used a2-adrenoceptor agonist for sedation, analgesia, and stress management. The central sympatholytic effects are augmented by peripheral inhibition of sympathetic ganglion transmission. The mechanism is not clear. ⋯ In conclusion, DMED dose-dependently inhibits INa and IACh in rat SCG neurons by preferential binding to the inactivated state of the Na(+) channels and the closed state (resting) of nAChR channels respectively. Both inhibitions are a2-adrenoceptor independent. Furthermore, the nAChR channels in rat SCG neurons are much more sensitive to inhibition by DMED than Na(+) channels.
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Previous studies have established the importance of the fronto-parietal brain network in the information processing of reasoning. At the level of cortical source analysis, this eletroencepalogram (EEG) study investigates the functional reorganization of the theta-band (4-8Hz) neurocognitive network of mathematically gifted adolescents during deductive reasoning. ⋯ Further correlation analyses have shown that the enhanced workspace configuration with respect to the global topological metrics of the theta network in math-gifted subjects is correlated with the intensive frontal midline theta (fm theta) response that is related to strong neural effort for cognitive events. These results suggest that by investing more cognitive resources math-gifted adolescents temporally mobilize an enhanced task-related global neuronal workspace, which is manifested as a highly integrated fronto-parietal information processing network during the reasoning process.