Brain recruitment of dendritic cells following Li-pilocarpine induced status epilepticus in adult rats

Activation of inflammatory and immune pathways may contribute to the development of epilepsy. Dendritic cells (DCs), a heterogeneous group of professional antigen presenting cells, can be detected in the brain under several inflammatory conditions. However, the spatiotemporal distribution and origin of seizure-induced DCs accumulation in the brain have not been explored yet. In the present study, we demonstrate the presence of CD11c-positive DCs in the hippocampus, thalamus and temporal cortex following Li-pilocarpine induced status epilepticus (SE) in rats. Recruitment of DCs occurs as early as 1 day following the induction of SE, reaching peak time at day 3, and still evident until day 5. The recruitment of DCs in the brain following lithium chloride administration was not detected. The observed DCs cannot be double-labeled with Iba-1 (an activated microglia marker) and whole-body radiation prevents seizure-induced DCs accumulation in brain parenchyma. Our data suggest that the recruitment of DCs in the epileptic brain may be derived from peripheral circulation and this population of immune cells may be involved in the immune processes after SE.