Reviews of Physiology, Biochemistry and Pharmacology, Volume 83

Volume 83 of the series Reviews of Physiology, Biochemistry and Pharmacology pp 35-88


Optical measurement of membrane potential

  • Lawrence B. CohenAffiliated withDepartment of Physiology, Yale University School of Medicine
  • , Brian M. SalzbergAffiliated withDepartment of Physiology and Pharmacology, School of Dental Medicine and Institute of Neurological Sciences, University of Pennsylvania

* Final gross prices may vary according to local VAT.

Get Access


Optical measurement of membrane potential is a new tool for physiologists and has already found many applications. However, the number of possible pitfalls is alarming, particularly in situations where comparison with electrode measurements is impossible. Exhaustive and elaborate controls are clearly necessary; and yet they never provide complete assurance that an optical signal represents a change in membrane potential. In our opinion, the use of redistribution signals, which are slower, and thus more likely to represent to secondary effects of changes in membrane potential, and require permeant dyes with access to the internal millieu, may be more hazardous than the use of either fast or intrinsic signals. However, the larger size of the redistribution signals has endowed them with obvious appeal. If more sensitive fast signals can be found, the use of this kind of signal would be facilitated.

Even though optical methods for measuring membrane potential were introduced relatively recently, their uses have multiplied rapidly and will doubtless continue to proliferate. It seems likely that, in several instances, optical techniques will prove to be quite powerful and, used with caution, should provide information unobtainable by other methods.