A Non-invasive Approach to Study the Electrophysiology of Motor Neurons in Zebrafish Embryos

Source: Benedetti, L., et al. Biosensing Motor Neuron Membrane Potential in Live Zebrafish Embryos. J. Vis. Exp. (2017). This video demonstrates a non-invasive assay to study electrophysiology of motor neurons in zebrafish embryos. Upon measuring tail coiling in the embryos as a result of spontaneous depolarization of the spinal cord motor neurons, a sodium channel blocker is applied to reduce the coiling frequency. Next, the embryos are immobilized in agarose and placed under a fluorescence microscope. The genetically engineered motor neurons express a voltage-sensing biosensor with a donor and an acceptor fluorophore. A decrease in acceptor fluorophore emission indicates a reduction in the spontaneous depolarization of motor neurons due to the sodium channel blocker.