The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), School of Health Management and Institute of Mental Psychology, Guangzhou Medical University, Guangzhou 511495, China.
Department of Pain Management, State Key Specialty in Pain Medicine, Guangzhou Medical University Second Affiliated Hospital, Guangzhou 510260, China.
eNeuro. 2024 Mar 8;11(3). doi: 10.1523/ENEURO.0272-23.2024. Print 2024 Mar.
Human and animal imaging studies demonstrated that chronic pain profoundly alters the structure and the functionality of several brain regions and even causes mental dysfunctions such as depression and anxiety disorders. In this article, we conducted a multimodal study cross-sectionally and longitudinally, to evaluate how neuropathic pain affects the brain. Using the spared nerve injury (SNI) model which promotes long-lasting mechanical allodynia, results showed that neuropathic pain deeply modified the intrinsic organization of the brain functional network 2 weeks after injury. There are significant changes in the activity of the left thalamus (Th_L) and left olfactory bulb (OB_L) brain regions after SNI, as evidenced by both the blood oxygen level-dependent (BOLD) signal and c-Fos expression. Importantly, these changes were closely related to mechanical pain behavior of rats. However, it is worth noting that after morphine administration for analgesia, only the increased activity in the TH region is reversed, while the decreased activity in the OB region becomes more prominent. Functional connectivity (FC) and c-Fos correlation analysis further showed these two regions of interest (ROIs) exhibit different FC patterns with other brain regions. Our study comprehensively revealed the adaptive changes of brain neural networks induced by nerve injury in both cross-sectional and longitudinal dimensions and emphasized the abnormal activity and FC of Th_L and OB_L in the pathological condition. It provides reliable assistance in exploring the intricate mechanisms of diseases.
人类和动物的影像学研究表明，慢性疼痛会深刻改变多个大脑区域的结构和功能，甚至导致抑郁和焦虑障碍等精神功能障碍。在本文中，我们进行了一项横向和纵向的多模态研究，以评估神经病理性疼痛如何影响大脑。使用促进长期机械性痛觉过敏的 spared nerve injury (SNI) 模型，结果表明，神经病理性疼痛在损伤后 2 周内深刻改变了大脑功能网络的内在组织。SNI 后，左丘脑 (Th_L) 和左嗅球 (OB_L) 脑区的活动发生了显著变化，这一点从血氧水平依赖 (BOLD) 信号和 c-Fos 表达中都可以得到证明。重要的是，这些变化与大鼠的机械性疼痛行为密切相关。然而，值得注意的是，在给予吗啡进行镇痛后，只有 TH 区域的活性增加得到了逆转，而 OB 区域的活性降低变得更加明显。功能连接 (FC) 和 c-Fos 相关分析进一步表明，这两个感兴趣区域 (ROI) 与其他脑区表现出不同的 FC 模式。我们的研究全面揭示了神经损伤在横向和纵向维度上引起的大脑神经网络的适应性变化，并强调了 Th_L 和 OB_L 在病理状态下的异常活动和 FC。它为探索疾病的复杂机制提供了可靠的帮助。
