Identification of Neural Circuits by Imaging Coherent Electrical Activity with FRET-Based Dyes

• Published in: Neuron (Cambridge, Mass.) Vol. 23; no. 3; pp. 449 - 459
• Main Authors: Cacciatore, Timothy W., Brodfuehrer, Peter D., Gonzalez, Jesus E., Jiang, Tao, Adams, Stephen R., Tsien, Roger Y., Kristan, William B., Kleinfeld, David
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.1999
• Subjects: Animals; Cell Membrane - physiology; Electrophysiology - methods; Fluorescent Dyes; Ganglia, Invertebrate - cytology; Ganglia, Invertebrate - physiology; Hirudo; Interneurons - cytology; Interneurons - physiology; Leeches; Microscopy, Fluorescence - methods; Motor Neurons - cytology; Motor Neurons - physiology; Movement - physiology; nerve cord; Nervous System - cytology; Neural Pathways; Swimming - physiology
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/S0896-6273(00)80799-0

We show that neurons that underlie rhythmic patterns of electrical output may be identified by optical imaging and frequency-domain analysis. Our contrast agent is a two-component dye system in which changes in membrane potential modulate the relative emission between a pair of fluorophores. We demonstrate our methods with the circuit responsible for fictive swimming in the isolated leech nerve cord. The output of a motor neuron provides a reference signal for the phase-sensitive detection of changes in fluorescence from individual neurons in a ganglion. We identify known and possibly novel neurons that participate in the swim rhythm and determine their phases within a cycle. A variant of this approach is used to identify the postsynaptic followers of intracellularly stimulated neurons.