研究人员发现，周围神经损伤后，小胶质细胞会降解细胞外基质结构，即脊髓背角第I层的神经元周围网络（PNN）。I层PNN选择性地包裹着脊髓背角投射神经元，这些神经元整合脊髓中的痛觉信息，并将其传达给脊柱上的大脑区域，从而诱发痛觉。小胶质细胞对PNN的降解增强了投射神经元的活动，并诱发了与疼痛有关的行为。因此，神经损伤诱导的PNN降解是一种机制，小胶质细胞选择性地增强脊髓痛觉回路的输出，并导致痛觉过敏。
据介绍，周围神经损伤后脊髓背角的小胶质细胞的激活有助于痛觉过敏的发展。被激活的小胶质细胞如何选择性地增强脊髓痛觉回路的活动还不是很清楚。
附：英文原文
Title: Microglia-mediated degradation of perineuronal nets promotes pain
Author: Shannon Tansley, Ning Gu, Alba Urea Guzmán, Weihua Cai, Calvin Wong, Kevin Lister, Einer Muoz-Pino, Noosha Yousefpour, R Brian Roome, Jordyn Heal, Neil Wu, Annie Castonguay, Graham Lean, Elizabeth M Muir, Artur Kania, Masha Prager-Khoutorsky, Ji Zhang, Christos G. Gkogkas, James W. Fawcett, Luda Diatchenko, Alfredo Ribeiro-da-Silva, Yves De Koninck, Jeffrey S. Mogil, Arkady Khoutorsky
Issue&Volume: 2022-05-26
Abstract: Activation of microglia in the spinal cord dorsal horn following peripheral nerve injury contributes to the development of pain hypersensitivity. How activated microglia selectively enhance the activity of spinal nociceptive circuits is not well understood. We discovered that following peripheral nerve injury, microglia degrade extracellular matrix structures, perineuronal nets (PNNs), in lamina I of the spinal cord dorsal horn. Lamina I PNNs selectively enwrap spinoparabrachial projection neurons, which integrate nociceptive information in the spinal cord and convey it to supraspinal brain regions to induce pain sensation. Degradation of PNNs by microglia enhances the activity of projection neurons and induces pain-related behaviors. Thus, nerve injury-induced degradation of PNNs is a mechanism by which microglia selectively augment the output of spinal nociceptive circuits and cause pain hypersensitivity.
DOI: abl6773
Source: https://www.science.org/doi/10.1126/science.abl6773