Excitation mapping with the organic cation AGB2+.

Excitation mapping is a method of visualizing the signaling history of neurons with permeant organic cations. It is compatible with high-resolution imaging, allowing concurrent visualization of all neuronal classes and their glutamate-gated excitation histories. Excitation mapping documents the stability and precision of neuronal signaling within a given neuronal class, arguing that single unit electrophysiological sampling accurately reflects neuronal diversity. We here review the theory of excitation mapping, provide methods and protocol links; outline imaging concepts; provide parametric data on the temporal range and physiological sensitivity of excitation mapping; and show that immunocytochemical methods for macromolecules are compatible with excitation mapping.