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Inositol trisphosphate‐induced hyperpolarization in rat dorsal root ganglion neurons
Author(s) -
Wang Z.,
Ypey D.L.,
Van Duijn B.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80602-d
Subject(s) - hyperpolarization (physics) , dorsal root ganglion , egta , depolarization , biophysics , membrane potential , chemistry , patch clamp , electrophysiology , intracellular , neuroscience , calcium , biochemistry , biology , sensory system , stereochemistry , organic chemistry , nuclear magnetic resonance spectroscopy
Inositol 1,4,5‐trisphosphate (1,4,5‐InsP 3 ) was perfused into rat dorsal root ganglion (DRG) neurons by whole‐cell patch‐clamp electrodes, while measuring the membrane potential. This operation evoked a transient (2–3 min) membrane hyperpolarization of about −15 mV (from −42 mV) followed by a depolarization. The membrane hyperpolarization was abolished when 30 mM EGTA was perfused together with 1,4,5‐InsP 3 or when 0.2 mM quinine was added to the bath solution. The hyperpolarizing response was enhanced when a low‐Ca 2+ EGTA‐free intracellular solution was used. Two InsP 2 isomers induced a different response. Our results suggest that the hyperpolarization is due to 1,4,5‐InsP 3‐ induced Ca 2+ release which may trigger Ca‐sensitive K + channels to open. Present results show that cultured DRG neurons are able to respond to 1,4,5‐InsP 3 perfusion in the whole‐cell configuration.