Neuroscience
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Traumatic brain injury (TBI) is a public health problem that causes high mortality and disability worldwide. Secondary brain damage from this type of injury may cause brain edema, blood-brain barrier destruction, and neurological dysfunction. MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression at the post-transcriptional level and play vital roles in maintaining and regulating physiological function. ⋯ Some special miRNAs in blood were used in clinical trials for TBI diagnosis and prognosis prediction. Treatment with miRNA agomirs or antagomirs alleviated the lesion volume and improved neurological deficits post-injury. We review the current progress of miRNA studies in TBI patients and animal models and identify the prospects and difficulties involved in the clinical applications of miRNAs.
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Extensive studies have indicated brain function connectivity abnormalities in autism spectrum disorder (ASD). However, there is a lack of longitudinal or cross-sectional research focused on tracking age-related developmental trends of autistic children at an early stage of brain development or based on a relatively large sample. The present study examined brain network changes in a total of 186 children both with and without ASD from 3 to 11 years, an early and key development period when significant changes are expected. ⋯ The main findings of the study were as follows: (1) From the connectivity analysis, several inter-regional synchronizations with reduction were identified in the younger and older ASD groups, and several intra-regional synchronization increases were observed in the older ASD group. (2) From the graph analysis, a reduced clustering coefficient and enhanced mean shortest path length in specific frequencies was observed in children with ASD. (3) Results suggested an age-related decrease of the mean shortest path length in the delta and theta bands in TD children, whereas atypical age-related alteration was observed in the ASD group. In addition, graph measures were correlated with ASD symptom severity in the alpha band. These results demonstrate that abnormal neural communication is already present at the early stages of brain development in autistic children and this may be involved in the behavioral deficits associated with ASD.
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Non-invasive brain stimulation is widely used to investigate and manipulate specific brain functions to broaden knowledge about healthy people, and also to provide for a potential treatment option for people with various psychopathological disorders that do not adequately benefit from traditional treatments. Nevertheless, the underlying mechanisms have not been fully investigated yet. The aim of the present study was to investigate whether we could alter the brain activity during a test for executive functioning. ⋯ Instead, we found a significant increase in deoxygenated hemoglobin [HHb] while performing the control task in the left anodal/right cathodal stimulation group compared to sham. Interestingly, also an influence on the mood of our participants was observed. These results are of importance especially regarding a better understanding of the influence of the dlPFC on the VFT.
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We are constantly exposed to socially conflicting situations in everyday life, and cognitive flexibility is essential for adaptively coping with such difficulties. Flexible goal choice and pursuit are not exclusively conscious, and therefore cognitive flexibility involves both explicit and implicit forms of processing. However, it is unclear how individual differences in explicit and implicit aspects of flexibility are associated with neural activity in a resting state. ⋯ Furthermore, the fALFF values in both regions predicted individual preference for flexible decision-making strategy in a vignettes simulation task. These results add to our understanding of the neural mechanisms underlying flexible decision-making for solving social conflicts. More generally, our findings highlight the utility of RS-fMRI combined with both explicit and implicit psychometric measures for better understanding individual differences in social cognition.
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Xanthurenic acid (XA), formed from 3-hydroxykynurenine (3-HK) in the kynurenine pathway of tryptophan degradation, may modulate glutamatergic neurotransmission by inhibiting the vesicular glutamate transporter and/or activating Group II metabotropic glutamate receptors. Here we examined the molecular and cellular mechanisms by which 3-HK controls the neosynthesis of XA in rat, mouse and human brain, and compared the physiological actions of 3-HK and XA in the rat brain. In tissue homogenates, XA formation from 3-HK was observed in all three species and traced to a major role of kynurenine aminotransferase II (KAT II). ⋯ The effect of 3-HK was reduced in the presence of the KAT inhibitor aminooxyacetic acid. Finally, both 3-HK and XA reduced the power of gamma-oscillatory activity recorded from the hippocampal CA3 region. Endogenous XA, newly formed from 3-HK, may therefore play a physiological role in attentional and cognitive processes.