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Distinct ASIC currents are expressed in rat putative nociceptors and are modulated by nerve injury
Author(s) -
Poirot Olivier,
Berta Temugin,
Decosterd Isabelle,
Kellenberger Stephan
Publication year - 2006
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/jphysiol.2006.113035
Subject(s) - dorsal root ganglion , acid sensing ion channel , nociceptor , application specific integrated circuit , neuroscience , neurite , nociception , microbiology and biotechnology , neuropathic pain , chemistry , biology , in vitro , receptor , ion channel , spinal cord , biochemistry , computer science , computer hardware
The H + ‐gated acid‐sensing ion channels (ASICs) are expressed in dorsal root ganglion (DRG) neurones. Studies with ASIC knockout mice indicated either a pro‐nociceptive or a modulatory role of ASICs in pain sensation. We have investigated in freshly isolated rat DRG neurones whether neurones with different ASIC current properties exist, which may explain distinct cellular roles, and we have investigated ASIC regulation in an experimental model of neuropathic pain. Small‐diameter DRG neurones expressed three different ASIC current types which were all preferentially expressed in putative nociceptors. Type 1 currents were mediated by ASIC1a homomultimers and characterized by steep pH dependence of current activation in the pH range 6.8–6.0. Type 3 currents were activated in a similar pH range as type 1, while type 2 currents were activated at pH < 6. When activated by acidification to pH 6.8 or 6.5, the probability of inducing action potentials correlated with the ASIC current density. Nerve injury induced differential regulation of ASIC subunit expression and selective changes in ASIC function in DRG neurones, suggesting a complex reorganization of ASICs during the development of neuropathic pain. In summary, we describe a basis for distinct cellular functions of different ASIC types in small‐diameter DRG neurones.