Optical probing of sodium dynamics in neurons and astrocytes

• DOI: 10.1016/j.neuroimage.2011.06.074
• Publication Date: 2011-07-07T07:11:33Z
• Authors: Christophe M. Lamy; Jean-Yves Chatton
• Keywords: Cerebral Cortex; Neurons; 0303 health sciences; Microscopy, Confocal; Patch-Clamp Techniques; Action Potentials; Reproducibility of Results; Action Potentials/physiology; Algorithms; Animals; Astrocytes/metabolism; Cells, Cultured; Cerebral Cortex/cytology; Computer Simulation; Electrophysiological Phenomena; Fluorescent Dyes; Kinetics; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Microscopy, Fluorescence; Neurons/metabolism; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sodium/metabolism; Somatosensory Cortex/metabolism; In Vitro Techniques; Electrophysiological Phenomena; Rats; Mice, Inbred C57BL; Rats, Sprague-Dawley; Kinetics; Mice; 03 medical and health sciences; Microscopy, Fluorescence; Astrocytes; Animals; Computer Simulation; Algorithms; Cells, Cultured; Fluorescent Dyes

Changes in intracellular Na(+) concentration underlie essential neurobiological processes, but few reliable tools exist for their measurement. Here we characterize a new synthetic Na(+)-sensitive fluorescent dye, Asante Natrium Green (ANG), with unique properties. This indicator was excitable in the visible spectrum and by two-photon illumination, suffered little photobleaching and located to the cytosol were it remained for long durations without noticeable unwanted effects on basic cell properties. When used in brain tissue, ANG yielded a bright fluorescent signal during physiological Na(+) responses both in neurons and astrocytes. Synchronous electrophysiological and fluorometric recordings showed that ANG produced accurate Na(+) measurement in situ. This new Na(+) indicator opens innovative ways of probing neuronal circuits.