Neuroscience
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Poststroke depression (PSD) is a common complication of stroke and has long been a serious threat to human health. PSD greatly affects neurological recovery, quality of life and mortality. Recent studies have shown that 5-hydroxymethylcytosine (5hmC), an important epigenetic modification, is enriched in the brain and associated with many neurological diseases. ⋯ In particular,DhMRs were strongly enriched in genes with lymphoid enhancer factor 1 (LEF1) binding motifs. Finally, we demonstrated that decreases in TET2 expression in the brain caused PSD by decreasing Wnt/β-catenin/LEF1 pathway signaling to promote inflammatory factor IL-18 expression. In conclusion, our data highlight the potential for 5hmC modification as a therapeutic target for PSD.
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Emotion plays an important role in people's lives. However, the neural mechanism of affective perception is still unclear. In this study, steady-state visual evoked potentials (SSVEPs) were used to explore information processing speed and interactions among cortical structures involved in affective perception. ⋯ Unpleasant emotions had the fastest information processing speed in the ventral stream compared with pleasant and neutral emotions, including the middle occipital gyrus and the middle temporal gyrus, with a right hemisphere bias. In addition, unpleasant emotions were stronger than pleasant emotions in long-term causal connections in the bilateral middle temporal gyrus, and the direction was from the right hemisphere to the left hemisphere. These results provide unique insights into the cortical activities for affective perception and support the view that unpleasant emotions have priority in information perception in the middle temporal gyrus compared with pleasant and neutral emotions, with a right hemisphere bias.
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Human behaviour amazes with extraordinary flexibility and the underlying neural mechanisms have often been studied using task switching. Despite extensive research, the relative importance of "cognitive" and "motor" aspects during switching is unclear. In the current study we examine this question combining EEG analysis techniques and source localization to examine whether the selection of the response, or processes during the execution of the response, contribute most to switching effects. ⋯ On a functional neuroanatomical level, these modulations in motor processes showed a clear temporal sequence in that motor codes are processed primarily in superior parietal regions (Brodman area 7) and only then in premotor regions (Brodman area 6). The observed modulations may reflect motor reprogramming processes. The study shows how EEG signal analysis in combination with brain mapping methods can inform debates on theories of human cognitive flexibility.
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Somatodendritic missorting of the axonal protein TAU is a hallmark of Alzheimer's disease and related tauopathies. Rodent primary neurons and iPSC-derived neurons are used for studying mechanisms of neuronal polarity, including TAU trafficking. However, these models are expensive, time-consuming, and/or require the killing of animals. ⋯ We demonstrate that the N-terminal half of TAU is not sufficient for axonal targeting, as a C-terminus-lacking construct (N-term-TAUHA) is not axonally enriched in both neuronal cell models. Importantly, SH-SY5Y-derived neurons do not show the formation of a classical axon initial segment (AIS), indicated by the lack of ankyrin G (ANKG) and tripartite motif-containing protein 46 (TRIM46) at the proximal axon, which suggests that successful axonal TAU sorting is independent of classical AIS formation. Taken together, our results provide evidence that (i) SH-SY5Y-derived neurons are a valuable human neuronal cell model for studying TAU sorting readily accessible at low cost and without animal need, and that (ii) efficient axonal TAU targeting is independent of ANKG or TRIM46 enrichment at the proximal axon in these neurons.
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Maternal opioids abuse has some deleterious consequences on next generations. Besides, children's rearing conditions can affect the behavioral states and brain plasticity in their later life. In the present study, we investigated the effects of maternal morphine (MOR) treatment and post-weaning rearing conditions on memory, pain threshold, and the ventral striatum dopaminergic activity in male offspring. ⋯ At molecular level, maternal MOR injections and social isolation reduced DA levels and altered expressions of D1R, D2R, and DAT within the ventral striatum of these male offspring. However, post-weaning EE partially buffered these changes. Our finding signified the effects of maternal MOR exposure and social isolation on the behaviors and neurochemistry of brain in next generation, and it also provided evidence on reversibility of these alterations following EE.