TY - JOUR
T1 - Glutamate-gated chloride channel with glutamate-transporter-like properties in cone photoreceptors of the tiger salamander
AU - Picaud, S. A.
AU - Larsson, H. P.
AU - Grant, G. B.
AU - Lecar, H.
AU - Werblin, F. S.
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1995
Y1 - 1995
N2 - 1. Using the patch-clamp technique, we investigated whether the glutamate elicited current in mechanically isolated cone photoreceptors from the salamander retina is generated by a Cl- channel or a glutamate transporter. 2. The current reversed near the equilibrium potential for Cl-, was decreased by three Cl- channel blockers, 5-nitro-2-(3-phenyl-propylamino) benzoic acid, 4,4'-diisothiocyanostilbene-2,2'-disulfonate, and diphenylamine 2,2'-dicarboxylic acid, and was eliminated when gluconate was substituted for both internal and external Cl-, features consistent with the current being mediated by a Cl- channel. 3. The single-channel conductance of the Cl- channel was estimated by noise analysis of the glutamate-elicited current fluctuations to be 0.7 pS with an open time of 2 ms. 4. The magnitude of the current was dependent on both internal and external Na+ and K+, features consistent with the current being related to the activation of a glutamate transporter. Yet changes in their concentrations did not affect the reversal potential of the current. 5. Taken together with earlier reports on this current showing that it has a glutamate-transporter-like pharmacology, our results suggest that the glutamate elicited current is carried by a Cl- channel but gated by a glutamate receptor whose pharmacology and ionic requirement resemble those previously described for glutamate transporters.
AB - 1. Using the patch-clamp technique, we investigated whether the glutamate elicited current in mechanically isolated cone photoreceptors from the salamander retina is generated by a Cl- channel or a glutamate transporter. 2. The current reversed near the equilibrium potential for Cl-, was decreased by three Cl- channel blockers, 5-nitro-2-(3-phenyl-propylamino) benzoic acid, 4,4'-diisothiocyanostilbene-2,2'-disulfonate, and diphenylamine 2,2'-dicarboxylic acid, and was eliminated when gluconate was substituted for both internal and external Cl-, features consistent with the current being mediated by a Cl- channel. 3. The single-channel conductance of the Cl- channel was estimated by noise analysis of the glutamate-elicited current fluctuations to be 0.7 pS with an open time of 2 ms. 4. The magnitude of the current was dependent on both internal and external Na+ and K+, features consistent with the current being related to the activation of a glutamate transporter. Yet changes in their concentrations did not affect the reversal potential of the current. 5. Taken together with earlier reports on this current showing that it has a glutamate-transporter-like pharmacology, our results suggest that the glutamate elicited current is carried by a Cl- channel but gated by a glutamate receptor whose pharmacology and ionic requirement resemble those previously described for glutamate transporters.
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U2 - 10.1152/jn.1995.74.4.1760
DO - 10.1152/jn.1995.74.4.1760
M3 - Article
C2 - 8989410
AN - SCOPUS:0028786382
VL - 74
SP - 1760
EP - 1771
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 4
ER -