title: Monitoring Integrated Activity of Individual Neurons Using FRET-Based Voltage-Sensitive Dyes.
abstract: Pairs of membrane-associated molecules exhibiting fluorescence resonance energy transfer (FRET) provide a sensitive technique to measure changes in a cell's membrane potential. One of the FRET pair binds to one surface of the membrane and the other is a mobile ion that dissolves in the lipid bilayer. The voltage-related signal can be measured as a change in the fluorescence of either the donor or acceptor molecules, but measuring their ratio provides the largest and most noise-free signal. This technology has been used in a variety of ways; three are documented in this chapter: (1) high throughput drug screening, (2) monitoring the activity of many neurons simultaneously during a behavior, and (3) finding synaptic targets of a stimulated neuron. In addition, we provide protocols for using the dyes on both cultured neurons and leech ganglia. We also give an updated description of the mathematical basis for measuring the coherence between electrical and optical signals. Future improvements of this technique include faster and more sensitive dyes that bleach more slowly, and the expression of one of the FRET pair genetically.
authors.affiliation: Circuit Dynamics and Connectivity Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA, kevin.briggman@nih.gov.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Briggman
authors.forename: William B
authors.initials: WB
authors.lastname: Kristan
authors.forename: Jesús E
authors.initials: JE
authors.lastname: González
authors.forename: David
authors.initials: D
authors.lastname: Kleinfeld
authors.forename: Roger Y
authors.initials: RY
authors.lastname: Tsien
mesh_terms: D000818:Animals; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D017952:Ganglia, Invertebrate / Q000502:physiology* / Q000648:ultrastructure; D057166:High-Throughput Screening Assays; D007865:Leeches; D008564:Membrane Potentials / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D059629:Signal-To-Noise Ratio; D059010:Single-Cell Analysis / Q000295:instrumentation / Q000379:methods; D013569:Synapses / Q000502:physiology / Q000648:ultrastructure; D056969:Voltage-Sensitive Dye Imaging / Q000295:instrumentation / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes