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As a complex physiological and psychological phenomenon, pain has a wide impact on the quality of life of patients. Chronic pain represents one of the most challenging public health issues, and ensuring effective pain management is not only a fundamental right of individuals but also a sacred duty of healthcare providers. This review focuses on recent advancements (within the past five years) in understanding how electroacupuncture (EA) alleviates pain-related affective disorders, such as anxiety and depression. By integrating findings from clinical trials and mechanistic studies, we highlight three key mechanisms: (1)Brain functional regulation: EA modulates brain regions (e.g., prefrontal cortex, insula, thalamus) and networks (default mode network, salience network) via functional magnetic resonance imaging (fMRI)-observed functional connectivity changes. (2)Neurotransmitter and receptor modulation: EA regulates pain and emotions by altering BDNF, β-endorphin, TRPV1, NMDARs, and P2Y12 receptor signaling, supported by studies on chronic pain and depression models. (3)Immune factor adjustment: EA reduces neuroinflammation by targeting TLR4/NF-κB pathways and pro-inflammatory cytokines (IL-1β, TNF-α), improving pain-related affective disorders. Clinical and preclinical evidence demonstrates EA's safety, efficacy, and multi-target effects, however, optimal treatment parameters and individualized strategies require further investigation. Future research should combine multi-omics, large-scale multi-center clinical studies , and precision medicine approaches to deepen understanding of EA's mechanisms and clinical applications. Show less

Chronic pain (CP) is increasingly recognized not only as a sensory and emotional condition but also as a significant contributor to cognitive dysfunction. Growing evidence indicates that CP-induced cognitive dysfunction arises from a cascade of neurobiological processes, including persistent neuroinflammation, neurotransmitter dysregulation, and impaired synaptic plasticity. These mechanisms particularly affect the hippocampus and medial prefrontal cortex (mPFC)-regions essential for memory, attention, and executive function. Neuroimaging studies have documented structural atrophy and disrupted network connectivity in these brain areas in CP patients. At the molecular level, pro-inflammatory cytokines such as interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) impair glutamatergic and GABAergic signaling, disrupt long-term potentiation (LTP), and inhibit neurogenesis. Additionally, dysregulation of brain-derived neurotrophic factor (BDNF) signaling exacerbates synaptic vulnerability, contributing to cognitive decline. These mechanistic overlaps are particularly relevant in aging populations and in Alzheimer's disease (AD), where CP may act as a risk factor. This review integrates clinical and preclinical findings on CP-related cognitive dysfunction, outlines key molecular mechanisms, and explores emerging therapeutic strategies targeting inflammation, neurotransmitter systems, and synaptic repair. Understanding the interaction between chronic pain and cognition is critical for developing precision treatments that address both nociceptive and neurodegenerative pathways. Show less

Chronic pain (CP) and major depressive disorder (MDD) are highly disabling global diseases, and their high comorbidity creates a bidirectional vicious cycle, significantly exacerbating functional impairment and treatment resistance. Multidisciplinary evidence suggests that the comorbid nature arises from deep functional coupling and neural network remodeling between the sensory-pain and emotional systems, rather than merely a symptom overlap. Neuroimaging, animal models, and neuromodulation studies demonstrate that key brain regions, including the prefrontal cortex (PFC), anterior cingulate cortex (ACC), amygdala, hippocampus, insula, and reward system, show consistent abnormalities in the comorbid state, creating a cross-brain network that jointly regulates pain, emotion, and cognition. This paper systematically reviews the central structures, neural circuits, and neurotransmitter regulatory mechanisms of CP-MDD comorbidity and proposes an integrated emotion-perception coupling network model. We highlight the mechanisms and translational potential of multi-pathway intervention strategies, with a focus on neuromodulation techniques (rTMS, tDCS), combined with ketamine, BDNF modulators, and anti-inflammatory drugs. Additionally, it is emphasized that future research must integrate multimodal imaging, multi-omics data, and computational modeling to establish a mechanism-driven personalized stratification system. With the support of high spatiotemporal resolution brain connectomics technology, this will facilitate the transition from a 'symptom control' to a 'mechanism repair' paradigm in treating comorbidities. Show less

Pain is common among adults with heart failure (HF), but pain subtypes and associated biomarkers are understudied. The aims were to: 1) characterize chronic pain severity, neuropathic pain quality, locations, and subtypes; and 2) compare pain severity and levels of biomarkers among pain subtypes. An exploratory aim was to correlate levels of biomarkers with pain severity. This pilot descriptive study included cross-sectional data from 60 adults with HF and chronic pain. Pain was evaluated using the PainDETECT questionnaire. Blood biomarkers included interleukin (IL)-10, IL-18, IL-1β, IL-33, IL-6, IL-8, tumor necrosis factor (TNF)-α, brain-derived neurotrophic factor, leptin, adiponectin, and C-reactive protein. Descriptive statistics, Chi-square test of homogeneity, one-way analysis of variance, and Spearman correlation were used for analyses. The mean age was 70.45 (SD 7.92) years. The sample consisted of 63.3% women and 65.0% White race. Participants primarily reported nociceptive pain only (73.3%) with fewer reporting neuropathic pain only (6.7%) and mixed pain (20.0%). Current and 4-week mean pain severity scores were highest in the mixed pain subtype (p both <.05). No biomarkers were significantly different across the pain subtypes, but lower lL-10 (p=.049), and IL-33 (p=.014), were associated with higher pain severity. In this study, chronic pain and its association with underlying biomarkers were characterized. Future research with a larger sample is needed to understand the unique contributions of biomarkers with targeted pain phenotypes. Show less

The activation of glial cells in the central nervous system plays an important role in the neural signaling of chronic pain and pruritus. However, their involvement in the neural signaling of chronic pain and pruritus in ACD remains to be investigated. To determine the effect of spinal glial cell activation in the coexistence of chronic pain and pruritus in the ACD model, we observed spinal glial cell activation in a mouse model of ACD induced by SADBE. Square acid dibutyl ester (SADBE) was employed to establish ACD model mice and monitor the activation of spinal cord glial cells. Additionally, the Gene Expression Omnibus (GEO) database was utilized to analyze potential mechanisms. In the ACD model, the behaviors of licking and biting within 35 days after modeling were significantly increased. The expression levels of Iba-1, BDNF, LCN2, GRPR, and GFAP differed significantly from those of the control group. In addition, through GEO data analyses, a strong correlation has been found between pain and IFN-γ. Similarly, in vitro experiments revealed that IFN-γ increased the expression of Iba-1, CD16, and BDNF in BV2 cells and the release of LCN2 in primary astrocytes, thus activating spinal cord glial cells. IFN-γ also induced the phosphorylation of JAK1/STAT1 and the expression of IFNGR1 in BV2 cells and primary astrocytes. Collectively, the above findings suggest that the coexistence of chronic pain and pruritus in the ACD model is associated with the activation of spinal microglia and astrocytes. The underlying mechanism involves the binding of IFN-γ to its receptor IFNGR1, which is accompanied by the upregulation of JAK1/STAT1 signaling pathway phosphorylation. Show less

Chronic pain, marked by nociceptive sensitization and maladaptive neuroplasticity, affects 30% of the global population with escalating socioeconomic burdens. Epidemiological data show a 2-3-fold increase in neuropsychiatric co-morbidities among individuals with chronic pain, where epigenetic dysregulation serves as a key mechanism linking ongoing pain to emotional disorders. This review systematically explores epigenetic signatures in supraspinal integration hubs, notably the limbic-paralimbic networks and prefrontal regulatory circuits. The identified epigenetic signatures encompass dysregulation of DNA methyltransferases (DNMTs), RNA modifications, histone post-translational modifications and locus-specific alterations, including aberrant methylation at the brain-derived neurotrophic factor (BDNF), opioid μ receptor and transient receptor potential ankyrin 1 (TRPA1) gene loci. Additionally, they involve dysfunction of the glucocorticoid receptor (GR)/corticotropin-releasing factor (CRF) axis via epigenetic modulation. Building on these findings, we evaluate therapeutic strategies addressing epigenetic dysregulation. While preclinical data demonstrate the efficacy of histone deacetylase (HDAC) and DNMT inhibitors, clinical translation faces significant barriers, including limited blood-brain barrier permeability. Notably, our analysis highlights the benefits of combining pharmacological interventions with non-invasive neuromodulation for enhanced co-morbidity management. Looking forward, this review proposes innovative approaches that leverage CRISPR-based chromatin editing platforms, biomimetic nanocarriers for neuron-specific delivery and closed-loop neuromodulation integrating real-time biomarker feedback, collectively establishing a precision medicine framework for pain or neuropsychiatric co-morbidities. Show less