Microglia Provide Structural Resolution to Injured Dendrites after Severe Seizures

Although an imbalance between neuronal excitation and inhibition underlies seizures, clinical approaches that target these mechanisms are insufficient in containing seizures in epileptic patients raising the need for alternative approaches. Brain-resident microglia contribute to the development and stability of neuronal structure and functional networks that are perturbed during seizures. However, the extent of microglial contributions in response to seizures in vivo remain to be elucidated.  Using two photon in vivo imaging to visualize microglial dynamics, we show that severe seizures induce microglial process pouch formation that target but rarely engulf beaded neuronal dendrites.  Microglial process pouches are stable for hours though they often shrink in size. We further found that microglial process pouches are associated with better structural resolution of beaded dendrites. These findings provide evidence for the structural resolution of injured dendrites by microglia as a form of neuroprotection.