Pain
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Pain is an unpleasant sensory and emotional experience. Both pain and emotions are warning signals against outside harm. Interoception, bodily sensations of emotions can be assessed with the emBODY tool where participants colour the body parts where they feel different emotions. ⋯ Patients and controls marked different body areas as sensitive to nociceptive and tactile stimulation, but there was no difference in sensitivity to hedonic touch. Our findings suggest that emotional processing changes when pain persists, and this can be assessed with these colouring tasks. BMoEs may offer a new approach to assessing pain.
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Endometriosis is a chronic gynaecological condition, of which pain is both the most common and most debilitating symptom. As with other forms of pain, there is increasing recognition of the role of psychological processes in bridging the gap between pain and pain impact, and yet these processes are not well understood in endometriosis. The aim of this study was to investigate the relevance of fear of progression, imagery, and interpretation bias in endometriosis, and their contribution to pain interference. ⋯ Controlling for age and pain intensity, we found that imagery, interpretation bias, and their interaction were associated with increased fear of progression and that fear of progression was associated with greater pain-related interference. In exploratory analysis, we also found that the frequency and distress of endometriosis-related intrusive imagery were associated with greater fear of progression and pain interference, after controlling for age and pain intensity. These findings provide the first support of the importance of fear of progression in people with endometriosis and suggest possible pathways for causal investigation.
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Pain associated with bone cancer remains poorly managed, and chemotherapeutic drugs used to treat cancer usually increase pain. The discovery of dual-acting drugs that reduce cancer and produce analgesia is an optimal approach. The mechanisms underlying bone cancer pain involve interactions between cancer cells and nociceptive neurons. ⋯ Inhibition of ATX or blockade of LPAR attenuated cancer exosome-evoked hypersensitivity in an ATX-LPA-LPAR-dependent manner. Parallel in vitro studies revealed the involvement of ATX-LPA-LPAR signaling in direct sensitization of dorsal root ganglion neurons by cancer exosomes. Thus, our study identified a cancer exosome-mediated pathway, which may represent a therapeutic target for treating tumor growth and pain in patients with bone cancer.
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Migraine is commonly reported in patients with temporomandibular disorders (TMDs), but little is known about the mechanisms underlying the comorbid condition. Here, we prepared a mouse model to investigate this comorbidity, in which masseter muscle tendon ligation (MMTL) was performed to induce a myogenic TMD, and the pre-existing TMD enabled a subthreshold dose of nitroglycerin (NTG) to produce migraine-like pain in mice. ⋯ Moreover, chemogenetic activation of Pdyn -expressing neurons or microinjection of dynorphin A (1-17) peptide in the Sp5C enabled a subthreshold dose of NTG to induce migraine-like pain in female mice but not in male mice. Taken together, our results suggest that trigeminal dynorphin has a female-specific role in the modulation of comorbid TMDs and migraine.