title: Non-invasive measurement of bioelectric currents with a vibrating probe.
abstract: Small d.c. electrical signals have been detected in many biological systems and often serve important functions in cells and organs. For example, we have recently found that they play a far more important role in directing cell migration in wound healing than previously thought. Here, we describe the manufacture and use of a simplified ultrasensitive vibrating probe system for measuring extracellular electrical currents. This vibrating probe is an insulated, sharpened metal wire with a small platinum-black tip (10-30 microm), which can detect ionic currents in the microA cm(-2) range in physiological saline. The probe is vibrated at about 300 Hz by a piezoelectric bender. In the presence of an ionic current, the probe detects a voltage difference between the extremes of its movement. The basic, low-cost system we describe is readily adaptable to most laboratories interested in measuring physiological electric currents associated with wounds, developing embryos and other biological systems.
authors.affiliation: School of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK.
authors.forename: Brian
authors.initials: B
authors.lastname: Reid
authors.forename: Richard
authors.initials: R
authors.lastname: Nuccitelli
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
mesh_terms: D000818:Animals; D004594:Electrophysiology / Q000295:instrumentation* / Q000379:methods*; D005110:Extracellular Space / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology*; D008839:Microelectrodes; D014732:Vibration
chemical_list: D007473:Ion Channels