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INTRODUCTION: According to previous studies, neuroinflammation may lead to an increase in seizure susceptibility and trigger epileptogenesis. However, emerging experimental evidence indicates that early age inflammation acting as a preconditioning factor may also have protective effects. Microglia are the immune competent cells of the CNS. After inflammation cellsretracttheir branches and transform into macrophages. Parameters of this morphological changes can be used as parameters of tissue reactivity to inflammation and seizures. AIM(S): The aim of this study was to examine the long term effects of systemic inflammation induced at different postnatal developmental stages on the range of morphological changes in microglial cells within brain cortex in response to status epilepticus experimentally evoked in adulthood. METHOD(S): Wistar rats were injected intraperitoneally with LPS on postnatal days 6 (P06) or 30 (P30). Two-month-old animals were injected with pilocarpine to evoke status epilepticus and sacrificed three days later. Brain sections were then processed for Iba-1 immunohistochemistry. A set of photographs were taken from several locations in the brain cortex and the automated Sholl analysis and morphometric measurements were performed. RESULTS: LPS injection alone on P06 and P30 causes significant decrease of critical radius and enclosing radius and significant increase of solidity. After seizures induced in adulthood statistically significant differences in all examined morphological parameters in both LPS-treated groups were observed. The morphology of microglia in rats’ cortex in P06 and P30 group after seizures is significantly closer to morphology of microglial cells in naïve rats. CONCLUSIONS: This imply that microglia in adult rat’s cortex after LPS injection alone in P06 or P30 are more ramified closer to the cell body. Also the longest processes are shorter after LPS injection than in naïve rats. This might result from long-term changes in nervous-tissue reactivity – preconditioning. FINANCIAL SUPPORT: Supported by NCS GRANT: UMO-2012/05/B/NZ4/02406.