European journal of pain : EJP
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Preoperative anxiety, a clinically significant problem for many patients undergoing surgery, is associated with prolonged and exacerbated post-operative pain. To date, the mechanisms of preoperative anxiety-induced persistent post-operative pain remain unclear. The present study aimed to provide a rat model of preoperative anxiety-induced persistent post-operative pain using the single-prolonged stress (SPS) procedure to induce preoperative anxiety-like behaviours, and to explore the role of spinal astrocytes in this phenomenon. ⋯ The data suggest that this rat model, which could mimic the clinical persistent post-operative pain induced by preoperative anxiety, may be a useful tool to explore the mechanisms as well as effective prevention and treatment for this problem. Furthermore, spinal astrocytes activation may contribute to the development of post-operative hyperalgesia in this model.
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Hypervigilance, i.e., excessive attention, is often invoked as a potential explanation for the observation that many individuals with fibromyalgia show a heightened sensitivity to stimulation in various sensory modalities, such as touch and hearing. Compelling evidence for this assumption is, however, lacking. The aim of the present study was to investigate the presence of somatosensory hypervigilance in patients with fibromyalgia. ⋯ No evidence was found to support the claim that patients with fibromyalgia display somatosensory hypervigilance. This finding challenges the idea of hypervigilance as a static feature of fibromyalgia and urges for a more dynamic view in which hypervigilance emerges in situations when bodily threat is experienced.
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Spinal microglia activation is one of the pathologic mechanisms involved in post-operative pain, which results from surgical injuries in skin, fascia, muscle and small nerves innervating these tissues. Recent research has shown that neuregulin-1 (NRG1) and its receptor erythroblastosis oncogene B (ErbB) family mediate microglia proliferation and chemotaxis contributing to the development of neuropathic pain. However, it is unclear whether NRG1-ErbB signalling contributes to incision-induced mechanical allodynia. ⋯ Incision-induced NRG1 expression mediated activation of dorsal horn microglia and contributed to the development of mechanical allodynia. Specifically targeting NRG1-ErbB signalling may therefore provide a new therapeutic intervention for relieving incision-induced mechanical allodynia.
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Attentional biases for pain-related information have been frequently reported in individuals with chronic pain. Recording of participants' eye movements provides a continuous measure of attention, although to date this methodology has received little use in research exploring attentional biases in chronic pain. The aim of the current investigation was to explore the specificity of attentional orienting bias using a novel visual search task while recording participant eye movement behaviours. This also allowed for the investigation of whether attentional biases for pain-related information exist in the presence of multiple stimuli competing for attention. ⋯ Individuals with chronic headache show facilitated initial orienting towards pain expressions specifically when used as targets in a visual search task. This study adds to a growing body of research supporting the presence of pain-related attentional biases in chronic pain as assessed via different experimental paradigms, and shows biases to exist when multiple stimuli competing for attention are presented simultaneously.
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African Americans are reported to be more sensitive to pain than European Americans. Pain sensitivity has been shown to be genetically linked in animal models and is likely to be in humans. ⋯ Greater African ancestry was associated with higher levels of self-reported pain, although this accounted for only a minor fraction of the overall variation in the Pain Construct.