Astrocytic Purinergic Signaling Coordinates Synaptic Networks

@article{Pascual2005AstrocyticPS,
  title={Astrocytic Purinergic Signaling Coordinates Synaptic Networks},
  author={Olivier Pascual and Kristen B. Casper and Cathryn L. Kubera and Jing Zhang and Raquel Revilla-Sanchez and Jai-Yoon Sul and Hajime Takano and Stephen J. Moss and Ken D. McCarthy and Philip G Haydon},
  journal={Science},
  year={2005},
  volume={310},
  pages={113 - 116}
}
To investigate the role of astrocytes in regulating synaptic transmission, we generated inducible transgenic mice that express a dominant-negative SNARE domain selectively in astrocytes to block the release of transmitters from these glial cells. By releasing adenosine triphosphate, which accumulates as adenosine, astrocytes tonically suppressed synaptic transmission, thereby enhancing the dynamic range for long-term potentiation and mediated activity-dependent, heterosynaptic depression. These… 
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References

SHOWING 1-10 OF 67 REFERENCES
Astrocyte-mediated potentiation of inhibitory synaptic transmission
TLDR
It is suggested that interneuronal firing elicits a GABAB-receptor-mediated elevation of calcium in surrounding astrocytes, which in turn potentiates inhibitory transmission, and Astrocytes may be a necessary intermediary in activity-dependent modulation of inhibitory synapses in the hippocampus.
Adenosine gates synaptic plasticity at hippocampal mossy fiber synapses
TLDR
It is shown that the unique presynaptic properties of the hippocampal mossy fiber synapse are largely imparted onto the synapse by the continuous local action of extracellular adenosine at Presynaptic A1Adenosine receptors, which maintains a low basal probability of transmitter release.
Glutamate induces calcium waves in cultured astrocytes: long-range glial signaling.
TLDR
It is reported that cultured hippocampal astrocytes can respond to glutamate with a prompt and oscillatory elevation of cytoplasmic free calcium, visible through use of the fluorescent calcium indicator fluo-3.
Glutamate‐dependent astrocyte modulation of synaptic transmission between cultured hippocampal neurons
TLDR
Functional consequences of elevating astrocyte calcium levels on co‐cultured neurons are determined and the possibility thatAstrocytes play a neuromodulatory role by controlling the extracellular level of glutamate is raised.
SNARE Protein-Dependent Glutamate Release from Astrocytes
TLDR
The Ca2+-dependent glutamate release from astrocytes is a SNARE protein-dependent process that requires the presence of functional vesicle-associated proteins, suggesting that astroCytes store glutamate in vesicles and that it is released through an exocytotic pathway.
ATP Released from Astrocytes Mediates Glial Calcium Waves
TLDR
The present experiments identify ATP as a major extracellular messenger in this system and implicate ATP as an important transmitter between CNS astrocytes.
The Role of Extracellular Adenosine in Regulating Mossy Fiber Synaptic Plasticity
TLDR
A reduction of the basal release probability by ambient adenosine does not underlie presynaptic forms of plasticity at mossy fiber synapses in mouse and rat hippocampal slices.
Hippocampal Astrocytes In Situ Respond to Glutamate Released from Synaptic Terminals
TLDR
The results suggest that hippocampal astrocytes in situ are able to respond to the neuronal release of the neurotransmitter glutamate with increases in [Ca2+]i, and suggest that higher levels of neuronal activity result in stimulation of both metabotropic and ionotropic glutamate receptors on the astroCytes.
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