Pain
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This study aims to investigate whether intranetwork dynamic functional connectivity and causal interactions of the salience network is altered in the interictal term of migraine. Thirty-two healthy controls, 37 migraineurs without aura, and 20 migraineurs with aura were recruited. Participants underwent a T1-weighted scan and resting-state fMRI protocol inside a 1.5T MR scanner. ⋯ Variance of dynamic conditional correlation was higher in migraine with aura vs healthy controls and migraine with aura vs without aura between the right insula and dorsal anterior cingulate cortex (P < 0.011, P < 0.026), and in migraine with aura vs healthy controls between the dorsal anterior cingulate and left prefrontal cortex (P < 0.021). Causality was weaker in the <0.05 Hz frequency range between the salience and dorsal attention networks in migraine with aura (P < 0.032). Overall, migraineurs with aura exhibit more fluctuating connections in the salience network, which also affect network interactions, and could be connected to altered cortical excitability and increased sensory gain.
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Despite large efforts to test analgesics in animal models, only a handful of new pain drugs have shown efficacy in patients. Here, we report a systematic review and meta-analysis of preclinical studies of the commercially successful drug pregabalin. Our primary objective was to describe design characteristics and outcomes of studies testing the efficacy of pregabalin in behavioral models of pain. ⋯ However, we were unable to show any clear relationships between preclinical design characteristics and effect sizes. Our findings suggest opportunities for improving the design and reporting of preclinical studies in pain. They also suggest that factors other than those explored in this study may be more important for explaining the discordance between outcomes in animal models of pain and those in clinical trials.
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Although ethnic differences in pain perception are well documented, the underlying mechanism for these outcomes has not been established. µ-opioid receptor (MOR) function might contribute to this disparity, given that MORs play a key role in pain sensitivity and modulation. However, no study has characterized ethnic differences in MOR physiology. This study sought to address this knowledge gap by examining differences in µ-selective agonist binding potential (BPND; [C]-Carfentanil) between 27 non-Hispanic black (NHB) and 27 demographically similar, non-Hispanic white participants. ⋯ Results suggest that NHB individuals might have generally greater unoccupied MOR density than non-Hispanic white peers. Findings have implications for physiological differences underlying ethnicity-related pain disparities. If replicated, these results further emphasize the need for tailored treatments in historically underserved populations.