Articles: hyperalgesia.
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The NLRP3 inflammasome is a multi-protein complex that assembles in response to tissue damage or infection, triggering activation of caspase-1, an enzyme that converts interleukin (IL)-1β into its active form. A role for the NLRP3 inflammasome is emerging in inflammatory pain, but its influence in other pain types is largely unexamined. Therefore the aim of this study was to assess the role of the NLRP3 inflammasome and its downstream product caspase-1 in a model of acute burn-induced pain in male mice. ⋯ Burn-induced edema was significantly reduced in Ice-/- mice only. Burn-induced weight bearing changes were attenuated in Nlrp3-/- mice and mice administered MCC950 72h after burn only. This study suggests that NLRP3 and its downstream product caspase-1 have a limited role in the development of burn-induced pain.
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Reg Anesth Pain Med · Mar 2017
Changes in Dorsal Root Ganglion Gene Expression in Response to Spinal Cord Stimulation.
Spinal cord stimulation (SCS) has been shown to influence pain-related genes in the spinal cord directly under the stimulating electrodes. There is limited information regarding changes occurring at the dorsal root ganglion (DRG). This study evaluates gene expression in the DRG in response to SCS therapy. ⋯ Spinal cord stimulation modulates expression of key pain-related genes in the DRG. Specifically, SCS led to reversal of IL-1b and IL-6 expression induced by injury. Interleukin 6 expression was still significantly larger than in sham animals, which may correlate to residual sensitivity following continuous SCS treatment. In addition, expression of GABAbr1 and Na/K ATPase was down-regulated to within control levels following SCS and correlates with applied current.
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Comparative Study
Cutaneous allodynia is more frequent in chronic migraine, and its presence and severity seems to be more associated with the duration of the disease.
To evaluate cutaneous allodynia among patients with chronic and episodic migraine in a tertiary headache clinic. ⋯ Cutaneous allodynia is more frequent in chronic migraine, and its presence and severity seems to be more associated with the duration of the disease.
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Tactile allodynia, a condition in which innocuous mechanical stimuli are perceived as painful, is a common feature of chronic pain. However, how the brain reorganizes in relation to the emergence of tactile allodynia is still largely unknown. This may stem from the fact that experiments in humans are cross-sectional in nature, whereas animal brain imaging studies typically require anaesthesia rendering the brain incapable of consciously sensing or responding to pain. ⋯ In contrast, nucleus accumbens and prefrontal brain areas displayed abnormal activity to normally innocuous stimuli when such stimuli induced tactile allodynia at 28 days after peripheral nerve injury, which had not been the case at 5 days after injury. Our data indicate that tactile allodynia-related nociceptive inputs are not observable in the primary somatosensory cortex BOLD response. Instead, our data suggest that, in time, tactile allodynia differentially engages neural circuits that regulate the affective and motivational components of pain.
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J Zhejiang Univ Sci B · Mar 2017
Effects of electroacupuncture at 2 and 100 Hz on rat type 2 diabetic neuropathic pain and hyperalgesia-related protein expression in the dorsal root ganglion.
To investigate the analgesic effects of electroacupuncture (EA) at 2 and 100 Hz on type 2 diabetic neuropathic pain (DNP) and on the expressions of the P2X3 receptor and calcitonin gene-related peptide (CGRP) in the dorsal root ganglion (DRG). ⋯ These findings indicate that EA at 2 Hz is a good option for the management of type 2 DNP. The EA effect may be related to its down-regulation of the overexpressions of the DRG P2X3 receptors and CGRP in this condition.