Expression and spatial distribution of P2X7 receptor in pilocarpine-induced epileptic rat hippocampus

Abstract

To investigate the dynamic expression and spatial distribution of P2X7 receptor in pilocarpine-induced epileptic rat hippocampus. Methods: Status epilepticus (SE) model of rats was established by intraperitoneal injection with chloride lithium and pilocarpine. Rat brain tissue and hippocampus were collected at 1, 3, 7, 14, 28 days after SE. The protein expression of P2X7 receptor in rat hippocampus was detected by Western blot. The distribution of P2X7 receptor in hippocampal sub-region was analyzed by immunohistochemistry. Results: Bilateral forelimb clonus appeared at (33.9±12.3) min after intraperitoneal injection with pilocarpine. The protein expression of P2X7 receptor was increased at 1d after SE, while it was decreased gradually from 3 d to minimum at 7 d, then it was elevated continuously to 28 d. Among them, the expression of P2X7 receptor was increased significantly at 1, 14 and 28 d post-SE (P<0.05). Immunohistochemical staining showed that P2X7 receptor was detected in all areas. The expression pattern of P2X7 receptor in hippocampal DG and CA3 area was consistent with protein expression, but its expression in hippocampal CA1 area was not significantly changed after SE. Conclusion: The expression of P2X7 receptor in post-SE hippocampus is in a time-dependent manner and spatial specificity. P2X7 receptor might be involved in the development of chronic epilepsy.