Neuroscience
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Parvalbumin-expressing (PV+) interneurons in the sensory cortex form powerful inhibitory synapses on the perisomatic compartments and axon initial segments of excitatory principal neurons (PNs), and perform diverse computational functions. Impaired PV+ interneuron functions have been reported in neural developmental and degenerative disorders. Expression of the unique marker parvalbumin (PV) is often used as a proxy of PV+ interneuron functions. ⋯ The expression of KV3.1 was correlated with spike frequency adaptation, but not with the expression of GAD67. These results suggest separate transcriptional regulations of PV/GAD67 vs. KV3.1, both of which are modulated by NIHL.
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Delayed paralysis occurs within some patients suffered from ischemic spinal cord injury (ISCI) due to the aorta occlusion during the repair surgery of thoracic and thoracoabdominal aortic aneurysms. Although mild hypothermia has been reported to improve ISCI and prolong the tolerance of rats to ISCI without inducing immediate paralysis, the mechanism remains unclear. Herein, the study revealed that the mild hypothermia treatment indeed partially improved the ISCI in rats caused by cross-clamping at the descending aorta. ⋯ In both in vivo ISCI model in rats and in vitro OGD model in BV-2 cells, the PI3K/AKT/mTOR pathway showed to be inhibited, whereas the PI3K/AKT/mTOR pathway was further inhibited by mild hypothermia in ISCI rats or rapamycin treatment in OGD-stimulated BV-2 cells. In conclusion, enhanced autophagy might be the mechanism of inhibited microglia activation by hypothermia treatment in ISCI rats and by rapamycin treatment in OGD-stimulated BV-2 cells. Autophagy could be enhanced through inhibiting the PI3K/AKT/mTOR pathway.
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Physical practice (PP) and motor imagery practice (MP) lead to the execution of fast and accurate arm movements. However, there is currently no information about the influence of MP on movement smoothness, nor about which performance parameters best discriminate these practices. In the current study, we assessed motor performances with an arm pointing task with constrained precision before and after PP (n = 15), MP (n = 15), or no practice (n = 15). ⋯ A discriminant analysis also identified the number of velocity peaks as the most relevant parameter that differentiated PP from MP. The current results provide evidence that PP and MP specifically modulate movement smoothness during arm reaching tasks. This difference may rely on online corrections through sensory feedback integration, available during PP but not during MP.
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Cerebral ischemia-reperfusion injury (IRI) is caused by reperfusion following ischemia. Mitophagy is closely related to cerebral IRI. Mitophagy disorder or excess may be harmful and lead to neuronal apoptosis. ⋯ Our research found that knockdown PRDX6 increased the expression of mitophagy-related and apoptosis-related proteins. Knocking down PINK1 relieved mitophagy and apoptosis caused by knocking down PRDX6. In conclusion, knockdown of PRDX6 could aggravate cerebral IRI by enhancing PINK1/PARKIN pathway mediated mitophagy, and this effect could increase neuronal apoptosis.
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The intermediate and deep layers of the optic tectum (OT) contain neurons that are sensitive to small continuously moving targets. The sensitivity of these neurons to continuously moving targets suggests directed energy accumulation in the dendrite field of these neurons. ⋯ We used the characteristics of continuous motion-sensitive neurons that prefer long-lasting motion and single dendrite activation to induce somatic spikes as the entry point to construct the neuron encoding model. This model will enhance our understanding of the information-processing mechanism of the OT area of bird neurons in perceiving weak targets, and has important theoretical and practical significance for the construction of new brain-like algorithms.