Brain research
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Caloric restriction (CR) has been shown to have several health benefits and provides protection against type 2 diabetes, neurodegenerative and cerebral vascular diseases. It reduces the brain infarct size and promotes neurological functional recovery after cerebral ischemia. Sirtuin 1 (SIRT1) plays an important role in the biological effects induced by CR. ⋯ CR increased the synthesis of SIRT1 significantly (p < 0.05), and ameliorated the down regulation of SIRT1 expression at 6 and 12h after middle cerebral artery occlusion (p < 0.05, p < 0 .01, respectively). Knockdown of SIRT1 by siRNA in vivo reversed the neuroprotective effect of CR. From this study, we deduce that CR induces brain ischemic tolerance on rats via increasing the synthesis of SIRT1.
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Receptor-interacting protein 3 (RIP3) is a key molecular switch in tumor necrosis factor-induced necroptosis requiring the formation of an RIP3-RIP1 complex. We have recently shown that hippocampal cornu ammonis 1 (CA1) neuronal death induced by 20-min global cerebral ischemia/reperfusion (I/R) injury is a form of programmed necrosis. However, the mechanism behind this process is still unclear and was studied here. ⋯ Decreased level of NAD+ in hippocampus and the release of cathepsin-B from lysosomes after I/R injury were also inhibited by Nec-1. Our data demonstrate that Nec-1 inhibits neuronal death by preventing RIP3 upregulation and nuclear translocation, as well as NAD+ depletion and cathepsin-B release. The nuclear translocation of RIP3 has not been reported previously, so this may be an important role for RIP3 during ischemic injury.
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Chronic pain is a pathological condition that results in significant loss of life quality, but so far no specific treatment for chronic pain has been developed. Currently available analgesia drugs are either not specific enough or have severe side effects. Therefore a non-invasive approach with high specificity to inhibit nociception becomes essential. ⋯ In vivo behavioral tests demonstrated that both the mechanical paw withdrawal threshold and the radiant heat evoked paw withdrawal latency were significantly increased upon illumination by a 532 nm green laser light to the paw of a viral-vector injected mice, while the same laser light did not induce any observable change in naïve mice. In conclusion, we have established a novel analgesic approach that can noninvasively and selectively inhibit pain transmission using an acute and controllable optogenetics method. This study may shed light on the application of a novel optogenetic strategy for the treatment of pain.
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Chronic tinnitus, also known as ringing in the ears, affects up to 15% of the adults and causes a serious socio-economic burden. At present, there is no treatment available which substantially reduces the perception of this phantom sound. In the past few years, preclinical and clinical studies have unraveled central mechanisms involved in the pathophysiology of tinnitus, replacing the classical periphery-based hypothesis. ⋯ A therapy with a potential to counteract deeply located pathological activity is deep brain stimulation, which has already been demonstrated to be effective in neurological diseases such as Parkinson's disease. In this review, several brain targets are discussed as possible targets for deep brain stimulation in tinnitus. The potential applicability of this treatment in tinnitus is discussed with examples from the preclinical field and clinical case studies.
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The nociceptive flexion reflex (NFR) is a widely used tool to investigate spinal nociception for scientific and diagnostic purposes, but its clinical use is currently limited due to the painful measurement procedure, especially restricting its applicability for patients suffering from chronic pain disorders. Here we introduce a less painful algorithm to assess the NFR threshold. Application of this new algorithm leads to a reduction of subjective pain ratings by over 30% compared to the standard algorithm. ⋯ Furthermore, we show that the new algorithm can be applied at shorter interstimulus intervals than are commonly used with the standard algorithm, since reflex threshold values remain unchanged and no habituation effects occur when reducing the interstimulus interval for the new algorithm down to 3s. Finally we demonstrate the utility of the new algorithm to investigate the modulation of nociception through different states of attention. Taken together, the here presented new algorithm could increase the utility of the NFR for investigation of nociception in subjects who were previously not able to endure the measurement procedure, such as chronic pain patients.