| First Author | Chen LQ | Year | 2023 |
| Journal | Br J Pharmacol | Volume | 180 |
| Issue | 8 | Pages | 1090-1113 |
| PubMed ID | 36443951 | Mgi Jnum | J:358883 |
| Mgi Id | MGI:7783762 | Doi | 10.1111/bph.15994 |
| Citation | Chen LQ, et al. (2023) Asymmetric activation of microglia in the hippocampus drives anxiodepressive consequences of trigeminal neuralgia in rodents. Br J Pharmacol 180(8):1090-1113 |
| abstractText | BACKGROUND AND PURPOSE: Patients suffering from trigeminal neuralgia are often accompanied by anxiety and depression. Microglia-mediated neuroinflammation is involved in the development of neuropathic pain and anxiodepression pathogenesis. Whether and how microglia are involved in trigeminal neuralgia-induced anxiodepression remains unclear. EXPERIMENTAL APPROACH: Unilateral constriction of the infraorbital nerve (CION) was performed to establish trigeminal neuralgia in rat and mouse models. Mechanical allodynia and anxiodepressive-like behaviours were measured. Optogenetic and pharmacological manipulations were employed to investigate the role of hippocampal microglia in anxiety and depression caused by trigeminal neuralgia. KEY RESULTS: Trigeminal neuralgia activated ipsilateral but not contralateral hippocampal microglia, up-regulated ipsilateral hippocampal ATP and interleukin-1beta (IL-1beta) levels, impaired ipsilateral hippocampal long-term potentiation (LTP) and induced anxiodepressive-like behaviours in a time-dependent manner in rodents. Pharmacological or optogenetic inhibition of ipsilateral hippocampal microglia completely blocked trigeminal neuralgia-induced anxiodepressive-like behaviours. Activation of unilateral hippocampal microglia directly elicited an anxiodepressive state and impaired hippocampal LTP. Knockdown of ipsilateral hippocampal P2X7 receptors prevented trigeminal neuralgia-induced microglial activation and anxiodepressive-like behaviours. Furthermore, we demonstrated that microglia-derived IL-1beta mediated microglial activation-induced anxiodepressive-like behaviours and LTP impairment. CONCLUSION AND IMPLICATIONS: These findings suggest that priming of microglia with ATP/P2X7 receptors in the ipsilateral hippocampus drives pain-related anxiodepressive-like behaviours via IL-1beta. An asymmetric role of the bilateral hippocampus in trigeminal neuralgia-induced anxiety and depression was uncovered. The approaches targeting microglia and P2X7 signalling might offer novel therapies for trigeminal neuralgia-related anxiety and depressive disorder. |
