Fluorescence changes during conduction in nerves stained with Acridine Orange.

Nerves from spider crabs anid squid fluoresce when staiined with Acridine Orange. The intenisity of fluorescence increases during nerse conduction. Prolongation of the electric response in the squid axon is associated with a fluorescence change of similar duration. These findings suggest that the physicochemical properties of the macromolecules around the dye molecules in the nerve membrane drastically change during the process of nerve conduction.