Figure 2.

Microglia in seizure-induced neurogenesis. Epileptic seizures increase neurogenesis as well as microglial activation in the dentate gyrus. In the stage of proliferation, activated microglia produce inflammatory cytokines, such as TNFα,⁴⁰ which suppress the aberrant proliferation of neural stem/progenitor cells. In the survival stage, our recent study⁴ revealed that both apoptotic and viable newborn cells in the dentate gyrus are phagocytosed and eliminated by microglia after status epilepticus. These studies demonstrate that microglia play a pivotal role in neurogenesis and in maintaining homeostasis of the dentate circuitry after epileptic seizures.