Neuroscience
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Randomized Controlled Trial
Dorsolateral Prefrontal Cortex and Task-Switching Performance: Effects of Anodal Transcranial Direct Current Stimulation.
Task switching refers to the process by which an individual transfers focus from one cognitive task to another. In recent years, transcranial direct current stimulation (tDCS) technology had been used to investigate the causal relationship between the dorsolateral prefrontal cortex (DLPFC) and task-switching performance. However, the effects of anodal-tDCS (a-tDCS) on task switching remain unclear, and the relationship between DLPFC and various task predictabilities have not yet been studied. ⋯ Compared with LA and sham tDCS, increasing the activity of the right DLPFC improved task-switching performance (switch cost) of unpredictable but not predictable tasks. The results suggested there is a causal association between DLPFC and unpredictable task switching and implied a task-specific effect in task switching. We concluded that the DLPFC is not essential for exogenous adjustment in predictable task switching.
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Melatonin is crucial for protecting neural stem cells (NSCs) from reactive oxygen species (ROS). However, the mechanism underlying these processes is unclear. In this study, we first investigated the significantly upregulated lncRNA MEG3 biomarker in the H2O2-induced NSCs and control groups. ⋯ In addition, the elevated miRNA-27a-3p decreased JNK phosphorylation by targeting MAP2K4. Overexpression of MAP2K4 suppressed the neuroprotective effects of miRNA-27a-3p. Therefore, melatonin appeared to protect NSCs from H2O2-induced ROS by modification of the MEG3/miRNA-27a-3p/MAP2K4 axis.
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The concentration of the multifunctional protein clusterin is reduced in the plasma of subjects with degenerative scoliosis (DS) and carpal tunnel syndrome (CTS) but elevated in the cerebrospinal fluid of neuropathic pain patients successfully treated with spinal cord stimulation. The present work tries to increase the knowledge of pain-associated changes of plasma and brain clusterin by using an animal model of neuropathy. We studied the effects of sciatic nerve ligation on mechanical allodynia (von Frey test), anxiety (elevated plus maze test), plasma clusterin (enzyme-linked immunosorbent assay) and clusterin expression in the nucleus accumbens (NAC) and prefrontal cortex (PFC) of adult male Wistar rats (western blot). ⋯ Animals with nerve ligation showed mechanical allodynia, anxiety and a marked downregulation of clusterin in the mitochondrial fraction of the prefrontal cortex. Animals fed on HF also exhibited a slight increase of the sensitivity to mechanical stimuli and anxiety; however, the diet did not potentiate the effects of nerve ligation. The results did not confirm a parallelism between neuropathy, obesity and alterations of plasma levels of clusterin, but strongly suggest that the protein could be involved in the functional reorganization of the prefrontal cortex which has been recently reported in chronic pain conditions.
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This study examined the processing of ambiguous morphemes in Chinese word recognition with a masked priming lexical decision task. Both behavioral and event-related potential (ERP) were recorded. All targets were bimorphemic compound words that contained ambiguous morphemes as the first morphemes. ⋯ These results have two implications to the processing of ambiguous morphemes during Chinese compound word recognition. First, the morpheme meanings could be activated rapidly. Second, the more frequently used dominant meanings could be activated more easily than the less frequently used subordinate meanings.
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Chronic inflammation might correlate with the formation of α-synuclein oligomers, subsequently leading to dopaminergic (DA) neuronal death in Parkinson's disease (PD). As major components of chronic inflammation, NOD-like receptor protein 3 (NLRP3) inflammasomes play a crucial role in PD via caspase 1 activation, primarily induced by mitochondrial damage. NLRP3 binds to apoptosis-associated speck-like protein containing a CARD (PYCARD/ASC), and forms inflammasomes in the brain. ⋯ Mutations to PRKN (encoding Parkin) are the most common cause of autosomal recessive familial and sporadic early-onset PD. Evidence has confirmed a relationship between Parkin and NLRP3 inflammasomes. In this review, we summarize the current understanding of NLRP3 inflammasomes and their role in PD progression, and discuss their regulation by Parkin.