Depression and pain disorders share a high degree of comorbidity. Inflammatory mechanisms play an important role in the pathogenesis of depression-chronic somatic pain comorbidity. In this study, we investigated the effects of acupuncture on blood and brain regional tumor necrosis factor alpha (TNF-α) in rats with depression and chronic somatic pain comorbidity. Forty Sprague-Dawley rats were randomly divided into the following 4 groups with 10 each: control, model, model treated with transcutaneous auricular vagus nerve stimulation (taVNS), and model treated with electroacupuncture (EA). Chronic unpredictable mild stress (CUMS) with chronic constriction injury of the sciatic nerve (CCI) was used to produce depression and chronic somatic pain comorbidity in the latter 3 groups. The rats of the taVNS and EA groups received, respectively, taVNS and EA at ST 36 for 28 days. Pain intensity was measured using a mechanical withdrawal threshold and thermal stimulation latency once biweekly. Depressive behavior was examined using a sucrose preference test at baseline and the end of modeling and intervention. The level of plasma TNF-α and the expression of TNF-α in the prefrontal cortex (PFC), hippocampus, amygdala, and hypothalamus were measured. While CUMS plus CCI produced remarkable depression-like behavior and pain disorders, EA and taVNS significantly improved depression and reduced pain intensity. CUMS plus CCI also resulted in a significant increase in plasma TNF-α level and the expression in all brain regions examined compared to the intact controls. Both EA and taVNS interventions, however, suppressed the elevated level of TNF-α. These results suggest that EA and taVNS have antidepressant and analgesic effects. Such effects may be associated with the suppression of TNF-α-related neuroinflammation.

中文翻译：

---

经皮耳部迷走神经刺激对抑郁-慢性躯体痛合并症大鼠外周和中枢肿瘤坏死因子α的影响

抑郁症和疼痛障碍具有高度的共病性。炎症机制在抑郁症-慢性躯体疼痛合并症的发病机制中起重要作用。在这项研究中，我们研究了针灸对血液和脑区域肿瘤坏死因子 α（TNF- α）的影响。) 在患有抑郁症和慢性躯体疼痛合并症的大鼠中。将 40 只 Sprague-Dawley 大鼠随机分为以下 4 组，每组 10 只：对照组、模型组、经皮耳迷走神经刺激（taVNS）治疗模型和电针（EA）治疗模型。慢性不可预测的轻度应激（CUMS）与坐骨神经（CCI）的慢性收缩性损伤被用来在后三组中产生抑郁症和慢性躯体疼痛合并症。tavns 和 EA 组的大鼠分别在 ST 36 时接受 tavns 和 EA 28 天。每两周一次使用机械退缩阈值和热刺激潜伏期测量疼痛强度。在基线和建模和干预结束时使用蔗糖偏好测试检查抑郁行为。血浆 TNF-α和 TNF- α在前额叶皮层 (PFC)、海马、杏仁核和下丘脑中的表达被测量。虽然 CUMS 加 CCI 产生了显着的抑郁样行为和疼痛障碍，但 EA 和 tavNS 显着改善了抑郁并降低了疼痛强度。与完整对照相比，CUMS 加 CCI 还导致血浆 TNF- α水平和所有大脑区域中的表达显着增加。然而，EA 和 tavns 干预均抑制了 TNF- α水平的升高。这些结果表明 EA 和 tavNS 具有抗抑郁和镇痛作用。这种作用可能与抑制 TNF- α相关的神经炎症有关。