Mechanisms of intercellular calcium signaling in glial cells studied with dantrolene and thapsigargin

Glia. 1993 Feb;7(2):134-45. doi: 10.1002/glia.440070203.


Mechanical stimulation of a single cell in a primary mixed glial cell culture induced a wave of increased intracellular calcium concentration ([Ca2+]i) that was communicated to surrounding cells. Following propagation of the Ca2+ wave, many cells showed asynchronous oscillations in [Ca2+]i. Dantrolene sodium (10 microM) inhibited the increase in [Ca2+]i associated with this Ca2+ wave by 60-80%, and prevented subsequent Ca2+ oscillations. Despite the markedly decreased magnitude of the increase in [Ca2+]i, the rate of propagation and the extent of communication of the Ca2+ wave were similar to those prior to the addition of dantrolene. Thapsigargin (10 nM to 1 microM) induced an initial increase in [Ca2+]i ranging from 100 nM to 500 nM in all cells that was followed by a recovery of [Ca2+]i to near resting levels in most cells. Transient exposure to thapsigargin for 2 min irreversibly blocked communication of Ca2+ wave from the stimulated cell to adjacent cells. Glutamate (50 microM) induced an initial increase in [Ca2+]i in most cells that was followed by sustained oscillations in [Ca2+]i in some cells. Dantrolene (10 microM) inhibited this initial [Ca2+]i increase caused by glutamate by 65-90% and abolished subsequent oscillations. Thapsigargin (10 nM to 1 micron) abolished the response to glutamate in over 99% of cells. These results suggest that while both dantrolene and thapsigargin inhibit intracellular Ca2+ release, only thapsigargin affects the mechanism that mediates intercellular communication of Ca2+ waves. These findings are consistent with the hypothesis that inositol trisphosphate (IP3) mediates the propagation of Ca2+ waves whereas Ca(2+)-induced Ca2+ release amplifies Ca2+ waves and generates subsequent Ca2+ oscillations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Brain / physiology
  • Caffeine / pharmacology
  • Calcium / metabolism*
  • Calcium-Transporting ATPases / antagonists & inhibitors
  • Cells, Cultured
  • Dantrolene / pharmacology*
  • Glutamates / pharmacology
  • Glutamic Acid
  • Kinetics
  • Neuroglia / drug effects
  • Neuroglia / physiology*
  • Physical Stimulation
  • Rats
  • Ryanodine / pharmacology
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*
  • Spectrometry, Fluorescence
  • Terpenes / pharmacology*
  • Thapsigargin


  • Glutamates
  • Terpenes
  • Ryanodine
  • Caffeine
  • Glutamic Acid
  • Thapsigargin
  • Calcium-Transporting ATPases
  • Dantrolene
  • Calcium