Neuroscience
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Recent studies have explored the circuitry involving the ventral hippocampus (vHPC), the amygdala, and the prefrontal cortex, a pathway mainly activated to store contextual information efficiently. Lesions in the vHPC impair remote memory, but not in the short term. However, how the vHPC is affected by distinct memory strength or its role in systems consolidation has not yet been elucidated. ⋯ The vHPC is required for the expression of remote fear memory and may control contextual fear generalization, a view corroborated by the fact that inactivation of the vHPC suppresses generalized fear expression, making memory more precise again. Systems consolidation occurs concomitantly with greater activation of the vHPC, which is accelerated in stronger fear memories. These findings lead us to propose that greater activation of the vHPC could be used as a marker for memory generalization.
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Ischemic heart disease is a fatal cardiovascular disease that irreversibly impairs the function of the heart, followed by reperfusion leading to a further increase in infarct size. Clinically, we call it myocardial ischemia-reperfusion injury (MIRI). A growing number of clinical observations and experimental studies have found electroacupuncture (EA) to be effective in alleviating MIRI. ⋯ The results were similar to the inhibition of glutamatergic neurons in FN. However, the activation of glutamatergic neurons in FN diminished the aforementioned effects of EA pretreatment. This study revealed that glutamatergic neurons in FN of the cerebellum is involved in EA pretreatment mediated sympathetic nervous and may be a potential mediator for improving MIRI.
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The benefits of aerobic exercises for memory are known, but studies of strength training on memory consolidation are still scarce. Exercise stimulates the release of metabolites and myokines that reaching the brain stimulate the activation of NMDA-receptors and associated pathways related to cognition and synaptic plasticity. The aim of the present study was to investigate whether the acute strength exercise could promote the consolidation of a weak memory. ⋯ Results showed that exercise induced the consolidation of a weak memory and this effect was dependent on the activation of NMDA-receptors. The hippocampal overexpression of BDNF and Synapsin I through exercise where NMDA-receptors dependent. Our findings showed that strength exercise strengthened fear memory consolidation and modulates the overexpression of BDNF and synapsin I through the activation of NMDA-receptors dependent signaling pathways.
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Increasing evidence suggests that alternative splicing plays a critical role in pain, but its underlying mechanism remains elusive. Herein, we employed complete Freund's adjuvant (CFA) to induce inflammatory pain in mice. A combination of genomics research techniques, lentivirus-based genetic manipulations, behavioral tests, and molecular biological technologies confirmed that splicing factor Cwc22 mRNA and CWC22 protein were elevated in the spinal dorsal horn at 3 days after CFA injection. ⋯ Comprehensive transcriptome and genome analysis identified the secreted phosphoprotein 1 (Spp1) as a potential gene of CWC22-mediated alternative splicing, however, only Spp1 splicing variant 4 (Spp1 V4) was involved in thermal and mechanical nociceptive regulation. In conclusion, our findings demonstrate that spinal CWC22 regulates Spp1 V4 to participate in CFA-induced inflammatory pain. Blocking CWC22 or CWC22-mediated alternative splicing may provide a novel therapeutic target for the treatment of persistent inflammatory pain.
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Most organisms on earth, humans included, have developed strategies to cope with environmental day-night and seasonal cycles to survive. For most of them, their physiological and behavioral functions, including the reproductive function, are synchronized with the annual changes of day length, to ensure winter survival and subsequent reproductive success in the following spring. Sheep are sensitive to photoperiod, which also regulates natural adult neurogenesis in their hypothalamus. ⋯ More specifically, the transition between LD and SD revealed negative BOLD responses to hypercapnia at the beginning of SD period followed by significant increases in BOLD, rCBV, Glx and tNAA concentrations towards the end of the SD period. These observations suggest longitudinal mechanisms promoting the proliferation and differentiation of neural stem cells within the hypothalamic niche of breeding ewes. We conclude that multiparametric MRI studies including 1H-MRS could be promising non-invasive translational techniques to investigate the existence of natural adult neurogenesis in-vivo in gyrencephalic brains.