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Stretch‐induced Ca 2+ independent ATP release in hippocampal astrocytes
Author(s) -
Xiong Yingfei,
Teng Sasa,
Zheng Lianghong,
Sun Suhua,
Li Jie,
Guo Ning,
Li Mingli,
Wang Li,
Zhu Feipeng,
Wang Changhe,
Rao Zhiren,
Zhou Zhuan
Publication year - 2018
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jp275805
Subject(s) - hippocampal formation , astrocyte , glutamate receptor , microbiology and biotechnology , synaptic vesicle , exocytosis , neurotransmission , biophysics , biology , neuroscience , chemistry , biochemistry , receptor , vesicle , secretion , central nervous system , membrane
Key points Similar to neurons, astrocytes actively participate in synaptic transmission via releasing gliotransmitters. The Ca 2+ ‐dependent release of gliotransmitters includes glutamate and ATP. Following an ‘on‐cell‐like’ mechanical stimulus to a single astrocyte, Ca 2+ independent single, large, non‐quantal, ATP release occurs. Astrocytic ATP release is inhibited by either selective antagonist treatment or genetic knockdown of P2X7 receptor channels. Our work suggests that ATP can be released from astrocytes via two independent pathways in hippocampal astrocytes; in addition to the known Ca 2+ ‐dependent vesicular release, larger non‐quantal ATP release depends on P2X7 channels following mechanical stretch.Abstract Astrocytic ATP release is essential for brain functions such as synaptic long‐term potentiation for learning and memory. However, whether and how ATP is released via exocytosis remains hotly debated. All previous studies of non‐vesicular ATP release have used indirect assays. By contrast, two recent studies report vesicular ATP release using more direct assays. In the present study, using patch clamped ‘ATP‐sniffer cells’, we re‐investigated astrocytic ATP release at single‐vesicle resolution in hippocampal astrocytes. Following an ‘on‐cell‐like’ mechanical stimulus of a single astrocyte, a Ca 2+ independent single large non‐quantal ATP release occurred, in contrast to the Ca 2+ ‐dependent multiple small quantal ATP release in a chromaffin cell. The mechanical stimulation‐induced ATP release from an astrocyte was inhibited by either exposure to a selective antagonist or genetic knockdown of P2X7 receptor channels. Functional P2X7 channels were expressed in astrocytes in hippocampal brain slices. Thus, in addition to small quantal ATP release, larger non‐quantal ATP release depends on P2X7 channels in astrocytes.