Mechanism of generation of spontaneous miniature outward currents (SMOCs) in retinal amacrine cells

The Journal of General Physiology
Pratip Mitra, Malcolm M Slaughter

Abstract

A subtype of retinal amacrine cells displayed a distinctive array of K(+) currents. Spontaneous miniature outward currents (SMOCs) were observed in the narrow voltage range of -60 to -40 mV. Depolarizations above approximately -40 mV were associated with the disappearance of SMOCs and the appearance of transient (I(to)) and sustained (I(so)) outward K(+) currents. I(to) appeared at about -40 mV and its apparent magnitude was biphasic with voltage, whereas I(so) appeared near -30 mV and increased linearly. SMOCs, I(to), and a component of I(so) were Ca(2+) dependent. SMOCs were spike shaped, occurred randomly, and had decay times appreciably longer than the time to peak. In the presence of cadmium or cobalt, SMOCs with pharmacologic properties identical to those seen in normal Ringer's could be generated at voltages of -20 mV and above. Their mean amplitude was Nernstian with respect to [K(+)](ext) and they were blocked by tetraethylammonium. SMOCs were inhibited by iberiotoxin, were insensitive to apamin, and eliminated by nominally Ca(2+)-free solutions, indicative of BK-type Ca(2+)-activated K(+) currents. Dihydropyridine Ca(2+) channel antagonists and agonists decreased and increased SMOC frequencies, respectively. Ca(2+) pe...Continue Reading

References

Jul 1, 1992·Biophysical Journal·F Thévenod, S W Jones
Aug 1, 1991·Journal of Bioenergetics and Biomembranes·O B McManus
Jan 20, 1987·Brain Research·L S Satin, P R Adams
Aug 1, 1987·Pflügers Archiv : European journal of physiology·S G RaneK Dunlap
Feb 1, 1987·The Journal of Physiology·T NarahashiM Yoshii
Apr 1, 1987·The Journal of Physiology·S A Lipton, D L Tauck
Jan 1, 1989·Annual Review of Physiology·B P Bean
Apr 1, 1985·Proceedings of the National Academy of Sciences of the United States of America·M C NowyckyR W Tsien
Jan 1, 1989·Annual Review of Physiology·R LatorreO Alvarez
Mar 1, 1986·Proceedings of the National Academy of Sciences of the United States of America·S Barnes, F Werblin
May 1, 1969·Journal of Neurophysiology·F S Werblin, J E Dowling
Jul 1, 1972·Proceedings of the National Academy of Sciences of the United States of America·D M Lam
Jun 1, 1973·The Journal of General Physiology·A M Woodhull
May 1, 1969·Journal of Neurophysiology·J E Dowling, F S Werblin
Oct 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·B P Bean
Jun 4, 1981·Nature·R P Swenson, C M Armstrong
Aug 1, 1981·Pflügers Archiv : European journal of physiology·O P HamillF J Sigworth
Oct 1, 1982·The Journal of Physiology·J N BarrettB S Pallotta
Jul 1, 1983·The American Journal of Physiology·A Fabiato
Mar 1, 1984·Biochemical Pharmacology·D C Pang, N Sperelakis
Jul 1, 1994·Pflügers Archiv : European journal of physiology·L J Janssen, S M Sims
Feb 1, 1995·Trends in Neurosciences·K DunlapT J Turner
Oct 27, 1995·Science·M T NelsonW J Lederer
May 1, 1995·The Journal of Cell Biology·X H SunC Franzini-Armstrong
Jan 1, 1994·The Japanese Journal of Physiology·K Kuba
Nov 1, 1994·Neuroscience·P Kostyuk, A Verkhratsky

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Citations

Oct 3, 2007·Visual Neuroscience·Pratip Mitra, Robert F Miller
Apr 14, 2009·Nature Neuroscience·William N GrimesJeffrey S Diamond
Aug 6, 2010·Journal of Neurophysiology·Merve Tekmen, Evanna Gleason
Jun 19, 2009·The Journal of Neuroscience : the Official Journal of the Society for Neuroscience·Satoshi Manita, William N Ross
Apr 29, 2008·The Journal of Physiology·Mingli HouMalcolm M Slaughter
Jun 22, 2005·Experimental Eye Research·David Krizaj
Apr 27, 2016·The Journal of Physiology·Jay Garaycochea, Malcolm M Slaughter
Nov 19, 2005·Journal of Neurophysiology·Ajithkumar WarrierMartin Wilson
Mar 22, 2003·Journal of Neurophysiology·Jozsef VighEric M Lasater

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Methods Mentioned

BETA
enzymatic dissociation

Software Mentioned

Clampex
Mini Analysis
Origin

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