Activation of mouse microglial cells affects P2 receptor signaling


  • T. Moeller
  • O. Kann
  • A. Verkhratsky
  • H. Kettenmann


  • Brain Research


  • Brain Res 853 (1): 49-59


  • Microglial cells are the immunocompetent cells of the CNS, which are known to exist in several activation states. Here we investigated the impact of microglial activation on the P2 receptor-mediated intracellular calcium ([Ca 2+](i)) signaling by means of fluo-3 based Ca 2+-imaging. Cultured mouse microglial cells were treated with either astrocyte-conditioned medium to induce a ramified morphology or LPS to shift the cells toward the fully activated stage. The extracellular application of ATP (100 μM) induced a [Ca 2+](i) elevation in 85% of both untreated and ramified microglial cells, whereas only 50% of the LPS-activated cells responded to the stimulus. To characterise the pharmacological profile of microglial P2 receptors we investigated the effects of various P2 agonists on [Ca 2+](i) in cultured microglial cells. Untreated and ramified microglial cells demonstrated a very similar sensitivity to the different P2 agonists. In contrast, in LPS-activated microglia, a sharp decrease of responses to P2 agonist stimulation was seen. This indicates that microglial activation influences the capability of microglial cells to generate [Ca 2+](i) signals upon P2 receptor activation.