Neuroscience
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Accumulating evidence indicates a positive effect of abacus-based mental calculation (AMC) training on various cognitive functions including short-term memory (STM). Our previous work has shown AMC training-induced activation changes in the frontal-parietal network (FPN) using task fMRI. However, whether AMC training-induced functional plasticity in the same brain network can be detected at resting state remains unknown. ⋯ In addition, a significant and positive correlation between letter forward memory span and SPL connectivity was found at post-training session in the AMC group. While the weakest quartile of SPL connections ranking by pre-training connectivity strength showed the largest effect of enhancement after training, it was the strongest quartile of SPL connectivity that correlated the most with memory span at post-training session. These findings suggest that AMC training may enhance bilateral SPL functional connectivity, through which AMC training might exert a transfer effect to improve short-term memory capacity.
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Chronic sleep-restriction (SR) is shown to be correlated with neurodevelopmental disorders. However, the effects of SR during stroke recovery on neurorepair remain unclear. In this study, mice were subjected to 60 min of cerebral ischemia followed by reperfusion. ⋯ The promoting roles of infiltrated CD169+ macrophages in post-stroke neurogenesis were due to increasing regulatory T cells (Tregs) in the ischemic brain parenchyma. Furthermore, dexmedetomidine treatment during SR increased CD169+ macrophages infiltration into the CP, CSF and ischemic brain parenchyma, and promoted neurogenesis and functional recovery. Taken together, our results showed that SR during stroke recovery decreased Tregs in the ischemic brain parenchyma by decreasing CD169+ macrophages infiltration to the ischemic brain parenchyma across the CP, which inhibited neurogenesis and functional recovery.
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Survivals after prenatal hypoxia-ischemia (HI) usually suffer long-lasting cognitive defects. Reduced blood-oxygen supplies and the following reperfusion cause mitochondrial injury. Damaged mitochondria could be replaced by mitochondrial biogenesis program and peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) is the specific up-regulator. ⋯ Postnatal administration of pioglitazone further promoted PGC-1α and mitochondrial biogenesis, alleviated hippocampal injury, and improved performance in the behavioral tasks after intrauterine HI. Our investigation implicated activation of PGC-1α, and mitochondrial biogenesis is a neuroprotective mechanism against brain injury caused by systemic prenatal HI. Promotion of PGC-1α by pioglitazone might be a potential treatment for protecting against hippocampal injury and cognitive defects after intrauterine HI.
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Myeloid zinc finger 1 (MZF1) belongs to the Kruppel family of zinc-finger transcription factors. Recent studies have demonstrated that in dorsal root ganglion (DRG) neurons, MZF1 is involved in the development and maintenance of neuropathic pain. However, the role of MZF1 in inflammatory pain still remains unknown. ⋯ The ChIP-PCR results revealed that MZF1 binds directly to the promoter region of MMP-2/9 gene. Together, the above results imply that upregulation of MZF1 in DRGs might contribute to the development and maintenance of CFA-induced chronic inflammatory pain by regulating MMP-2/9 and Kv1.2 expression. Targeting DRG-localized MZF1 might be a promising therapeutic strategy for the treatment of chronic inflammatory pain in the clinic.
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Inter-limb reflexes play an important role in coordinating behaviors involving different limbs. Previous studies have demonstrated that human elbow muscles express an inter-limb stretch reflex at long-latency (50-100 ms), a timing consistent with a trans-cortical linkage. Here we probe for inter-limb stretch reflexes in the shoulder muscles of human participants. ⋯ Inter-limb stretch reflexes were also observed at long-latency yet they were opposite to the preceding short-latency; when the short-latency stretch reflex was excitatory then the long-latency stretch reflex was inhibitory and vice versa. Comparing the responses to contralateral arm displacement to those during simultaneous displacement of both arms revealed that inhibitory inter-limb stretch reflexes are independent of within-limb stretch reflexes, but that excitatory inter-limb stretch reflexes are suppressed by within-limb stretch reflexes. Our results provide the first demonstration of short-latency inter-limb stretch reflexes in the upper limb of humans and reveal interacting spinal circuits for within-limb and inter-limb stretch reflexes.