A coronal section of rat brain cerebral cortex (presented above) was immunofluorescently labeled for heavy chain neurofilament subunits with chicken anti-NF-H antibodies followed by goat anti-chicken secondary antibodies conjugated to Alexa Fluor 568 (red fluorescence). Neurofilaments are specialized intermediate filaments chiefly found in the axons of neurons. In addition, the neuron-specific class III beta-tubulin isoform was targeted with mouse anti-beta-III-tubulin antibodies visualized with goat anti-mouse secondary antibodies conjugated to Alexa Fluor 488 (green fluorescence). Nuclear DNA was counterstained with DRAQ5 (pseudocolored blue). Images were recorded with a 20x objective using a zoom factor of 2.0 and sequential scanning with the 488-nanometer spectral line of an argon-ion laser, the 543-nanometer line from a green helium-neon laser, and the 633-nanometer line of a red helium-neon laser. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles unless otherwise noted above.