Pain
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A vast diversity of salient cues is sensed by numerous classes of primary sensory neurons, defined by specific neuropeptides, ion channels, or cytoskeletal proteins. Recent evidence has demonstrated a correlation between the expression of some of these molecular markers and transmission of signals related to distinct sensory modalities (eg, heat, cold, pressure). Voltage-gated sodium channel Na(v)1.8 has been reported to be preferentially expressed in small-diameter unmyelinated sensory afferents specialized for the detection of noxious stimuli (nociceptors), and Na(v)1.8-Cre mice have been widely used to investigate gene function in nociceptors. ⋯ We demonstrate that 75% of dorsal root ganglion (DRG) neurons express Na(v)1.8-Cre, including >90% of neurons expressing markers of nociceptors and, unexpectedly, a large population (∼40%) of neurons with myelinated A fibers. Furthermore, analysis of DRG neurons' central and peripheral projections revealed that Na(v)1.8-Cre is not restricted to nociceptors but is also expressed by at least 2 types of low-threshold mechanoreceptors essential for touch sensation, including those with C and Aβ fibers. Our results indicate that Na(v)1.8 underlies electrical activity of sensory neurons subserving multiple functional modalities, and call for cautious interpretation of the phenotypes of Na(v)1.8-Cre-driven conditional knockout mice.
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The importance of willingness to adopt a self-management approach to chronic pain has been demonstrated in the context of cognitive-behaviorally oriented interdisciplinary pain treatment programs for adults, both as a treatment outcome and as a process that facilitates functional improvements. Willingness to self-manage pain has not been studied in pediatric interdisciplinary pain treatment settings. Study aims were (1) to investigate willingness to self-manage pain among children and parents undergoing intensive interdisciplinary pain treatment and (2) to determine whether increased willingness to self-manage pain influenced functional treatment outcomes. ⋯ Increases in parents' readiness to adopt a pain self-management approach were associated with changes in parent-reported fear of pain but not with other child outcomes. Few associations emerged between pretreatment willingness to self-manage pain and posttreatment outcomes. Findings suggest that interdisciplinary pediatric pain rehabilitation may facilitate increased willingness to self-manage pain, which is associated with improvements in function and psychological well-being.
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Decoding pain in others is of high individual and social benefit in terms of harm avoidance and demands for accurate care and protection. The processing of facial expressions includes both specific neural activation and automatic congruent facial muscle reactions. While a considerable number of studies investigated the processing of emotional faces, few studies specifically focused on facial expressions of pain. ⋯ Moreover, pain faces were rated as most negative and highly arousing. Results suggest a general processing bias in favor of pain expressions. Findings are discussed in light of attentional demands of pain-related information and communicative aspects of pain expressions.