Neurons and glial cells, colored SEM. The nerve cells have small cell bodies (orange) and fine extensions called axons and dendrites (brown). The glial cells have large cell bodies (blue) with thicker extensions (pale green).
Second-harmonic generation microscopy image of a primary cultured Aplysia neuron stained with the membrane dye DHPESBP. (From Optical Recording of Action Potentials with Second-Harmonic Generation Microscopy, Daniel A. Dombeck et al.