HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 90/2/586    most recent 00007.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Buttner, N. Articles by Siegelbaum, S. A. Search for Related Content PubMed PubMed Citation Articles by Buttner, N. Articles by Siegelbaum, S. A.

Antagonistic Modulation of a Hyperpolarization-Activated Cl^– Current in Aplysia Sensory Neurons by SCP_B and FMRFamide

Center for Neurobiology and Behavior, Department of Pharmacology, Howard Hughes Medical Institute, Columbia University, New York City, New York 10032

Submitted 6 January 2003; accepted in final form 18 April 2003

Whole cell voltage-clamp recordings from Aplysia mechanosensory neurons obtained from the pleural ganglion were used to investigate the actions on membrane currents of the neuropeptides SCP_B and FMRFamide. At the start of whole cell recording, SCP_B typically evoked an inward current at a holding potential of –40 mV, due to the cAMP-mediated closure of the S-type K⁺ channel, whereas FMRFamide evoked an outward current, due to the opening of the S-type K⁺ channels mediated by 12-lipoxygenase metabolites of arachidonic acid. However, after several minutes of whole cell recording with a high concentration of chloride in the whole cell patch pipette solution, the responses to SCPB and FMRF-amide at –40 mV were inverted; SCP_B evoked an outward current, whereas FMRFamide and YGGFMRFamide evoked inward currents. Ion substitution experiments and reversal potential measurements revealed that these responses were due to the opposing regulation of a Cl^– current, whose magnitude was greatly enhanced by dialysis with the high Cl^–-containing pipette solution. SCP_B inhibited this Cl^– current through production of cAMP and activation of PKA. YGGFMRFamide activated this Cl^– current by stimulating a cGMP-activated phosphodiesterase that hydrolyzed cAMP. Thus a cAMP-dependent Cl^– current undergoes antagonistic modulation by two neuropeptides in Aplysia sensory neurons.

This article has been cited by other articles:

				U. Rose, C. Derst, M. Wanischeck, C. Marinc, and C. Walther Properties and possible function of a hyperpolarisation-activated chloride current in Drosophila J. Exp. Biol., July 15, 2007; 210(14): 2489 - 2500. [Abstract] [Full Text] [PDF]