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Blockers of potassium channels reduce the outward dark current in rod photoreceptor inner segments

Published online by Cambridge University Press:  02 June 2009

Kun Yan  and
Gary Matthews
Kun Yan
Affiliation:
Department of Neurobiology and Behavior, State University of New York, Stony Brook
Gary Matthews
Affiliation:
Department of Neurobiology and Behavior, State University of New York, Stony Brook
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Abstract

The dark current of single isolated toad rods was monitored by drawing either the inner segment or the outer segment into a suction electrode. The potassium-channel blockers tetraethylammonium (TEA) and 3,4-diaminopyridine (DAP) reduced the amplitude of the dark current when applied to the inner segment. Both drugs were less effective when applied to the outer segment, suggesting that they act at the inner segment to block part of the outward path for the dark current. In addition, DAP affected the kinetics of the light response, possibly by affecting internal pH.

Keywords

PhotoreceptorsPotassium channelsPhototransduction
Type
Short Communication
Information
Visual Neuroscience , Volume 8 , Issue 5 , May 1992 , pp. 479 - 481
Copyright
Copyright © Cambridge University Press 1992

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References

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