The journal of pain : official journal of the American Pain Society
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Threat-induced pain modulation can increase survival by amplifying physiological and behavioral reactions toward danger. Threat can also modulate spinal nociception, suggesting engagement of endogenous top-down circuitry. A unique method to assess spinal nociception is via reflex receptive fields (RRF) associated with the nociceptive withdrawal reflex (NWR, a protective spinally-mediated reflex). ⋯ This is likely mediated by top-down circuitry that enhances dorsal horn nociceptive neurons by enlarging RRFs and amplifying ascending pain signals. PERSPECTIVE: This article presents the enlargement of RRF during periods of threat. The results from this study may help clarify the mechanism underlining emotional modulation of spinal nociception.
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C-tactile (CT) fibers, responsible for the so-called "affective" touch (AT), have drawn a fair amount of attention within the scientific community for their marked social dimension. However, while the pain-relieving potential of discriminative touch (DT) has been documented, proofs of the analgesic properties of AT are still scarce. Additionally, no study has so far tested its possible pain-relieving effects on a clinically-relevant model. ⋯ Targeting CT fibers could pave the way to new treatments for chronic pain conditions whose aetiology depend on abnormal C-nociceptors' physiology. PERSPECTIVE: This study extends previous findings on the analgesic potential of affective touch, documenting a clear pain reduction during temporal summation of second pain (TSSP). Since TSSP is thought to reflect central sensitization, the psychophysiological mechanisms of affective touch could be exploited for new chronic pain treatments.
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Cannabidiol (CBD) is widely advertised as helpful for chronic pain management but research is limited. Using a cross-sectional, anonymous survey, we examined patterns of naturalistic CBD use among individuals with fibromyalgia (FM) and other chronic pain conditions. Our objective was to better understand rates of CBD use, reasons for use and discontinuation, communication with healthcare professionals about CBD, and perceptions of CBD effectiveness and safety among people with FM. ⋯ Our findings highlight the need for additional rigorous studies to better understand CBD's potential for FM management. PERSPECTIVE: This article indicates that CBD use is common among people with fibromyalgia, and the results suggest that many derive benefit from using CBD across multiple symptoms domains. Clinicians should discuss CBD use with fibromyalgia patients, and future studies are needed to rigorously assess CBD's therapeutic value for fibromyalgia symptoms.
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TACAN (Tmem120A), a mechanotransducing ion channel highly expressed in a subset of nociceptors, has recently been shown to contribute to detection of noxious mechanical stimulation. In the present study we evaluated its role in sensitization to mechanical stimuli associated with preclinical models of inflammatory and chemotherapy-induced neuropathic pain (CIPN). Intrathecal administration of an oligodeoxynucleotide antisense (AS-ODN) to TACAN mRNA attenuated TACAN protein expression in rat dorsal root ganglia (DRG). ⋯ PERSPECTIVE: We evaluated the role of TACAN, a mechanotransducing ion channel in nociceptors, in preclinical models of inflammatory and CIPN. Attenuation of TACAN expression reduced hyperalgesia produced by inflammatory mediators but had not chemotherapeutic agents. Our findings support the presence of multiple mechanotransducers in nociceptors.