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: 289/1/C224    most recent 00004.2005v1 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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kuznetsov, A. Articles by Philipson, L. H. Search for Related Content PubMed PubMed Citation Articles by Kuznetsov, A. Articles by Philipson, L. H.

CALL FOR PAPERS
Methods in Cell Physiology

FRET-based voltage probes for confocal imaging: membrane potential oscillations throughout pancreatic islets

Departments of ¹Medicine, ²Neurobiology, Pharmacology and Physiology, and ³Pediatrics, Division of Biological Sciences, Pritzker School of Medicine, The University of Chicago, Chicago, Illinois

Submitted 5 January 2005 ; accepted in final form 3 March 2005

Insulin secretion is dependent on coordinated pancreatic islet physiology. In the present study, we found a way to overcome the limitations of cellular electrophysiology to optically determine cell membrane potential (V_m) throughout an islet by using a fast voltage optical dye pair. Using laser scanning confocal microscopy (LSCM), we observed fluorescence (Förster) resonance energy transfer (FRET) with the fluorescent donor N-(6-chloro-7-hydroxycoumarin-3-carbonyl)-dimyristoylphosphatidyl-ethanolamine and the acceptor bis-(1,3-diethylthiobarbiturate) trimethine oxonol in the plasma membrane of essentially every cell within an islet. The FRET signal was approximately linear from V_m –70 to +50 mV with a 2.5-fold change in amplitude. We evaluated the responses of islet cells to glucose and tetraethylammonium. Essentially, every responding cell in a mouse islet displayed similar time-dependent changes in V_m. When V_m was measured simultaneously with intracellular Ca²⁺, all active cells showed tight coupling of V_m to islet cell Ca²⁺ changes. Our findings indicate that FRET-based, voltage-sensitive dyes used in conjunction with LSCM imaging could be extremely useful in studies of excitation-secretion coupling in intact islets of Langerhans.

pancreatic -cell; optical electrophysiology; islet electrical coupling