Biolistic loading of voltage-sensitive dyes into cells in rat brain slices for optical recording of neuron activity

摘要

Neuron electrical activity was recorded using an optical method in which the probes were widely used monomolecular voltage-sensitive dyes. Current methods of loading voltage-sensitive dyes into nervous tissue have serious limitations, severely restricting their areas of use (insolubility in water, the need for toxic organic solvents, and the toxicity of the voltage-sensitive dyes themselves at high concentrations). We have developed a new method of loading voltage-sensitive dyes by "shooting" dye-coated gold microparticles into living brain slices. Three-dimensional reconstruction of nervous tissue fluorescence with a scanning confocal microscope showed that after loading with dye by this method, it propagated along the cell membrane, completely staining only one target cell with its processes, without spreading to surrounding cells via the intercellular fluid or through cell contacts. This method of staining neurons can be used for the optical recording of the electrical activity of individual neurons and to analyze the distribution of electric voltages across the compartments of excitable cells (axons and dendrites).