Publication details
THE ACTIVATION OF GLIAL CELLS IN THE PERIAQUEDUCTAL GREY IN THE OROFACIAL NEUROPATHIC PAIN MODEL
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| Year of publication | 2022 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Orofacial (trigeminal) neuropathic pain (TNP) is still deemed a valid question for treatment. TNP is one of the most debilitating chronic neuropathic disorders resulting from injury of the trigeminal nerve or its branches. Periaqueductal grey (PAG) is a crucial midbrain structure involved in a wide variety of functions being also a gateway in the endogenous analgesic network. The ventrolateral periaqueductal grey (vlPAG) is significant for trigeminal nociceptive modulation. There is a lack of evidence about the correlation between trigeminal nerve injury and the cellular and molecular changes in vlPAG. Changes in glial activation and CX3CR1 were investigated in vlPAG of TNP induced by unilateral ligature of the infraorbital nerve (IONL). The naive, sham- and IONL-operated rats survived for 1, 3, 7, and 14 days (n=6 in each group) and were used for our experiments. The rats were perfused with Zamboni solution and brainstems were dissected. Transversal cryostat sections (20 µm) were immunostained to explore the activation of glial cells (OX42 for microglia, GFAP for astrocytes) and cellular immunodetection of CX3CR1. After the IONL, cellular and molecular changes were observed in vlPAG. The peak of the microglial activation was observed at POD1, while reactive astrocytes were increased from POD1 until POD14 compared with vlPAG from sham-operated rats. Both activated microglia and reactive astrocytes displayed a higher intensity of CX3CR1 immunofluorescence compared to naive. Activated microglial cells in vlPAG may be involved in the beginning, but reactive astrocytes in the maintenance of TNP. Our results suggested that signaling by chemokine receptor CX3CR1 may be involved in activated microglia as well as reactive astrocytes of vlPAG in the TNP experimental model. |
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