Activation of mouse microglial cells affects P2 receptor signaling

Brain Res. 2000 Jan 17;853(1):49-59. doi: 10.1016/s0006-8993(99)02244-1.


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 microM) 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / pharmacology
  • Aniline Compounds
  • Animals
  • Animals, Newborn
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • Calcium-Transporting ATPases / antagonists & inhibitors
  • Cells, Cultured
  • Corpus Callosum
  • Dose-Response Relationship, Drug
  • Down-Regulation
  • Endoplasmic Reticulum / metabolism
  • Extracellular Space / metabolism
  • In Vitro Techniques
  • Intracellular Fluid / metabolism
  • Lipopolysaccharides / pharmacology
  • Mice
  • Mice, Inbred Strains
  • Microglia / cytology
  • Microglia / drug effects
  • Microglia / metabolism*
  • Purinergic P2 Receptor Agonists
  • Receptors, Purinergic P2 / biosynthesis
  • Receptors, Purinergic P2 / metabolism*
  • Signal Transduction* / drug effects
  • Xanthenes


  • Aniline Compounds
  • Lipopolysaccharides
  • Purinergic P2 Receptor Agonists
  • Receptors, Purinergic P2
  • Xanthenes
  • Fluo-3
  • Adenosine Triphosphate
  • Calcium-Transporting ATPases
  • Calcium