QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, July 22, 2009, 29(29):9197-9209; doi:10.1523/JNEUROSCI.1240-09.2009

This Article Full Text Full Text (PDF) Supplemental Data Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Related articles in J. Neurosci. Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (1) Google Scholar Articles by Bradley, J. Articles by DiGregorio, D. A. PubMed PubMed Citation Articles by Bradley, J. Articles by DiGregorio, D. A.

 Previous Article  |  Next Article 

Cellular/Molecular
Submillisecond Optical Reporting of Membrane Potential In Situ Using a Neuronal Tracer Dye

Jonathan Bradley,¹ Ray Luo,² Thomas S. Otis,^1,2 and David A. DiGregorio¹

¹Centre National de la Recherche Scientifique UMR8118, Laboratoire de Physiologie Cérébrale, Université Paris Descartes, 75006 Paris, France, and ²Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095

Correspondence should be addressed to David A. DiGregorio, Centre National de la Recherche Scientifique UMR8118, Laboratoire de Physiologie Cérébrale, Université Paris Descartes, 45 rue des Saints Pères, 75006 Paris, France. Email: david.digregorio{at}univ-paris5.fr

A major goal in neuroscience is the development of optical reporters of membrane potential that are easy to use, have limited phototoxicity, and achieve the speed and sensitivity necessary for detection of individual action potentials in single neurons. Here we present a novel, two-component optical approach that attains these goals. By combining DiO, a fluorescent neuronal tracer dye, with dipicrylamine (DPA), a molecule whose membrane partitioning is voltage-sensitive, optical signals related to changes in membrane potential based on FRET (Förster resonance energy transfer) are reported. Using DiO/DPA in HEK-293 cells with diffraction-limited laser spot illumination, depolarization-induced fluorescence changes of 56% per 100 mV ( 0.1 ms) were obtained, while in neuronal cultures and brain slices, action potentials (APs) generated a F/F per 100 mV of >25%. The high sensitivity provided by DiO/DPA enabled the detection of subthreshold activity and high-frequency APs in single trials from somatic, axonal, or dendritic membrane compartments. Recognizing that DPA can depress excitability, we assayed the amplitude and duration of single APs, burst properties, and spontaneous firing in neurons of primary cultures and brain slices and found that they are undetectably altered by up to 2 µM DPA and only slightly perturbed by 5 µM DPA. These findings substantiate a simple, noninvasive method that relies on a neuronal tracer dye for monitoring electrical signal flow, and offers unique flexibility for the study of signaling within intact neuronal circuits.

---

Received March 12, 2009; revised June 2, 2009; accepted June 17, 2009.

Correspondence should be addressed to David A. DiGregorio, Centre National de la Recherche Scientifique UMR8118, Laboratoire de Physiologie Cérébrale, Université Paris Descartes, 45 rue des Saints Pères, 75006 Paris, France. Email: david.digregorio{at}univ-paris5.fr

Related articles in J. Neurosci.:

This Week in The Journal

J. Neurosci. 2009 29: i. [Full Text]  

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help