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Purinergic transmission and transglial signaling between neuron somata in the dorsal root ganglion
Author(s) -
Rozanski Gabriela M.,
Li Qi,
Kim Hyunhee,
Stanley Elise F.
Publication year - 2013
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12082
Subject(s) - dorsal root ganglion , purinergic receptor , microbiology and biotechnology , neurotransmission , neuron , chemistry , thapsigargin , bapta , neuroscience , biophysics , intracellular , receptor , biology , extracellular , biochemistry , sensory system
Most dorsal root ganglion neuronal somata ( NS ) are isolated from their neighbours by a satellite glial cell ( SGC ) sheath. However, some NS are associated in pairs, separated solely by the membrane septum of a common SGC to form a neuron–glial cell–neuron ( NG lN) trimer. We reported that stimulation of one NS evokes a delayed, noisy and long‐duration inward current in both itself and its passive partner that was blocked by suramin, a general purinergic antagonist. Here we test the hypothesis that NG lN transmission involves purinergic activation of the SGC . Stimulation of the NS triggered a sustained current noise in the SGC . Block of transmission through the NG lN by reactive blue 2 or thapsigargin, a Ca 2+ store‐depletion agent, implicated a Ca 2+ store discharge‐linked P2Y receptor. P2Y2 was identified by simulation of the NG lN‐like transmission by puffing UTP onto the SGC and by immunocytochemical localization to the SGC membrane septum. Block of the UTP effect by BAPTA , an intracellular Ca 2+ scavenger, supported the involvement of SGC Ca 2+ stores in the signaling pathway. We infer that transmission through the NG lN trimer involves secretion of ATP from the NS and triggering of SGC Ca 2+ store discharge via P2Y2 receptors. Presumably, cytoplasmic Ca 2+ elevation leads to the release of an as‐yet unidentified second transmitter from the glial cell to complete transmission. Thus, the two NS of the NG lN trimer communicate via a ‘sandwich synapse’ transglial pathway, a novel signaling mechanism that may contribute to information transfer in other regions of the nervous system.