Astrocytes potentiate transmitter release at single hippocampal synapses.
Astrocytes play active roles in brain physiology. They respond to neurotransmitters and modulate neuronal excitability and synaptic function. However, the influence of astrocytes on synaptic transmission and plasticity at the single synapse level is unknown. Ca(2+) elevation in astrocytes transiently increased the probability of transmitter release at hippocampal area CA3-CA1 synapses, without affecting the amplitude of synaptic events. This form of short-term plasticity was due to the release of glutamate from astrocytes, a process that depended on Ca(2+) and soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein and that activated metabotropic glutamate receptors (mGluRs). The transient potentiation of transmitter release became persistent when the astrocytic signal was temporally coincident with postsynaptic depolarization. This persistent plasticity was mGluR-mediated but N-methyl-d-aspartate receptor-independent. These results indicate that astrocytes are actively involved in the transfer and storage of synaptic information.
Perea
Gertrudis
G
Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Araque
Alfonso
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D019706:Excitatory Postsynaptic Potentials; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology; D017774:Long-Term Potentiation; D009473:Neuronal Plasticity; D018377:Neurotransmitter Agents / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission
D018377:Neurotransmitter Agents; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D000255:Adenosine Triphosphate; D002118:Calcium