New roles for astrocytes: regulation of synaptic transmission

Trends Neurosci. 2003 Oct;26(10):536-42. doi: 10.1016/S0166-2236(03)00237-6.


Abstract Although glia often envelop synapses, they have traditionally been viewed as passive participants in synaptic function. Recent evidence has demonstrated, however, that there is a dynamic two-way communication between glia and neurons at the synapse. Neurotransmitters released from presynaptic neurons evoke Ca2+ concentration increases in adjacent glia. Activated glia, in turn, release transmitters, including glutamate and ATP. These gliotransmitters feed back onto the presynaptic terminal either to enhance or to depress further release of neurotransmitter. Transmitters released from glia can also directly stimulate postsynaptic neurons, producing either excitatory or inhibitory responses. Based on these new findings, glia should be considered an active partner at the synapse, dynamically regulating synaptic transmission.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Astrocytes / metabolism*
  • Astrocytes / physiology
  • Brain / metabolism*
  • Brain / physiology
  • Calcium Signaling
  • Cell Communication
  • Glutamic Acid / metabolism
  • Humans
  • Neural Inhibition
  • Neuromuscular Junction / metabolism*
  • Neuromuscular Junction / physiology
  • Neurons / metabolism
  • Neurotransmitter Agents / metabolism
  • Presynaptic Terminals / metabolism*
  • Presynaptic Terminals / physiology
  • Retina / metabolism*
  • Retina / physiology
  • Signal Transduction
  • Synaptic Transmission*


  • Neurotransmitter Agents
  • Glutamic Acid
  • Adenosine Triphosphate