Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Permeability changes induced by L‐glutamate in solitary retinal horizontal cells isolated from Carassius auratus.

Permeability changes induced by L‐glutamate in solitary retinal horizontal cells isolated from... Solitary horizontal cells isolated from goldfish retinae are depolarized by L‐glutamate (Glu) (Ishida, Kaneko & Tachibana, 1984), a possible candidate for the transmitter of photoreceptors. The underlying mechanisms were analysed under voltage‐clamp conditions using 'giga‐seal' suction pipettes in the whole‐cell recording configuration. Glu induced an inward current at the resting membrane potential (ca. ‐57 mV). Membrane depolarization decreased the amplitude of Glu‐induced current and reversed its polarity to outward beyond approximately ‐3 mV. Membrane hyperpolarization below the resting potential decreased the amplitude of the Glu‐induced inward current. When a K current through the anomalous rectifier, which is activated by membrane hyperpolarization (Tachibana, 1983), was blocked by Cs ions, this phenomenon disappeared and the Glu‐induced current increased in amplitude with hyperpolarization. Mg ions had no effect on the reduction of the Glu‐induced current at hyperpolarized potentials. It was strongly suggested that Glu produced two types of conductance change; a conductance increase due to an activation of Glu channels and a conductance decrease due to a blockage of the K current through the anomalous rectifier. The latter effect is analysed in detail in the following paper (Kaneko & Tachibana, 1985b). The Glu‐activated channel was permeable to cations (Na, K, Ca, Mg, Tris and choline ions) with low selectivity, but not to anions. The least effective dose of Glu was less than 10 microM. The relation between the Glu‐induced current and the membrane potential curved upwards near the reversal potential, and this relation was not affected by Mg ions. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Physiology Wiley

Permeability changes induced by L‐glutamate in solitary retinal horizontal cells isolated from Carassius auratus.

Tachibana, M
The Journal of Physiology , Volume 358 (1) – Jan 1, 1985
Download PDF
15 pages

Loading next page...
 
/lp/wiley/permeability-changes-induced-by-l-glutamate-in-solitary-retinal-Mcfileoviv

References (26)

Publisher
Wiley
Copyright
© 2014 The Physiological Society
ISSN
0022-3751
eISSN
1469-7793
DOI
10.1113/jphysiol.1985.sp015545
Publisher site
See Article on Publisher Site

Abstract

Solitary horizontal cells isolated from goldfish retinae are depolarized by L‐glutamate (Glu) (Ishida, Kaneko & Tachibana, 1984), a possible candidate for the transmitter of photoreceptors. The underlying mechanisms were analysed under voltage‐clamp conditions using 'giga‐seal' suction pipettes in the whole‐cell recording configuration. Glu induced an inward current at the resting membrane potential (ca. ‐57 mV). Membrane depolarization decreased the amplitude of Glu‐induced current and reversed its polarity to outward beyond approximately ‐3 mV. Membrane hyperpolarization below the resting potential decreased the amplitude of the Glu‐induced inward current. When a K current through the anomalous rectifier, which is activated by membrane hyperpolarization (Tachibana, 1983), was blocked by Cs ions, this phenomenon disappeared and the Glu‐induced current increased in amplitude with hyperpolarization. Mg ions had no effect on the reduction of the Glu‐induced current at hyperpolarized potentials. It was strongly suggested that Glu produced two types of conductance change; a conductance increase due to an activation of Glu channels and a conductance decrease due to a blockage of the K current through the anomalous rectifier. The latter effect is analysed in detail in the following paper (Kaneko & Tachibana, 1985b). The Glu‐activated channel was permeable to cations (Na, K, Ca, Mg, Tris and choline ions) with low selectivity, but not to anions. The least effective dose of Glu was less than 10 microM. The relation between the Glu‐induced current and the membrane potential curved upwards near the reversal potential, and this relation was not affected by Mg ions.

Journal

The Journal of Physiology – Wiley

Published: Jan 1, 1985

There are no references for this article.