Background: Activation of G protein coupled receptor (GPCR) in astrocytes leads to Ca2+-dependent glutamate release via Bestrophin 1 (Best1) channel. Whether receptor-mediated glutamate release from astrocytes can regulate synaptic plasticity remains to be fully understood. Results: We show here that Best1-mediated astrocytic glutamate activates the synaptic N-methyl-D-aspartate receptor (NMDAR) and modulates NMDAR-dependent synaptic plasticity. Our data show that activation of the protease-activated receptor 1 (PAR1) in hippocampal CA1 astrocytes elevates the glutamate concentration at Schaffer collateral-CA1 (SC-CA1) synapses, resulting in activation of GluN2A-containing NMDARs and NMDAR-dependent potentiation of synaptic responses. Furthermore, the threshold for inducing NMDAR-dependent long-term potentiation (LTP) is lowered when astrocytic glutamate release accompanied LTP induction, suggesting that astrocytic glutamate is significant in modulating synaptic plasticity. Conclusions: Our results provide direct evidence for the physiological importance of channel-mediated astrocytic glutamate in modulating neural circuit functions.
Bibliographical noteFunding Information:
We thank Dr. T. Jacks for providing us with pSicoR lentiviral vector through Addgene Inc., Dr. R. Tsien for the pDisplay-GluSnFR vector, and Dr. K. McCarthy for hGFAP-CreERT2 transgenic mice. HP was supported by the Korea Institute of Science and Technology (KIST; Star-Postdoc. Fellowship). GM and RPL were supported by the Ente Cassa di Risparmio di Firenze. JS, S-HC, and S-Y C were supported by the Korea Research Foundation (KRF; grant 2014050477). SFT was supported by NIH (grant NS039419). CJL was supported by NIH (grant NS43875), KRF (grant KRF-2005-070-C00096), KIST institutional program (Project No. 2E25210), and Brain Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2012M3C7A1055412).
© 2015 Park et al.; licensee BioMed Central.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cellular and Molecular Neuroscience