Neuronal activity triggers calcium waves in hippocampal astrocyte networks

Neuron. 1992 Mar;8(3):429-40. doi: 10.1016/0896-6273(92)90271-e.

Abstract

The recent discovery that the neurotransmitter glutamate can trigger actively propagating Ca2+ waves in the cytoplasm of cultured astrocytes suggests the possibility that synaptically released glutamate may trigger similar Ca2+ waves in brain astrocytes in situ. To explore this possibility, we used confocal microscopy and the Ca2+ indicator fluo-3 to study organotypically cultured slices of rat hippocampus, where astrocytic and neuronal networks are intermingled in their normal tissue relationships. We find that astrocytic Ca2+ waves are present under these circumstances and that these waves can be triggered by the firing of glutamatergic neuronal afferents with latencies as short as 2 s. The Ca2+ waves closely resemble those previously observed in cultured astrocytes: they propagate both within and between astrocytes at velocities of 7-27 microns/s at 21 degrees C. The ability of tissue astrocyte networks to respond to neuronal network activity suggests that astrocytes may have a much more dynamic and active role in brain function than has been generally recognized.

Publication types

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

MeSH terms

  • Animals
  • Astrocytes / physiology*
  • Calcium / physiology*
  • Culture Techniques
  • Cytoplasm / physiology
  • Electric Stimulation
  • Extracellular Space / physiology
  • Glial Fibrillary Acidic Protein / metabolism
  • Hippocampus / physiology*
  • Microscopy, Fluorescence
  • N-Methylaspartate / pharmacology
  • Neural Pathways / physiology
  • Neurons / physiology*
  • Neurotransmitter Agents / physiology
  • Rats

Substances

  • Glial Fibrillary Acidic Protein
  • Neurotransmitter Agents
  • N-Methylaspartate
  • Calcium