In a double immunofluorescence experiment, this sagittal section of rat brain featuring the medulla oblongata was fixed, permeabilized, blocked with 10-percent normal goat serum, and then treated with primary chicken antibodies against NF-H (heavy chain neurofilament subunits) and rabbit antibodies against GFAP (glial fibrillary acidic protein). The primary targets were then visualized with goat anti-chicken secondary antibodies conjugated to Alexa Fluor 488 (green emission) and anti-rabbit antibodies conjugated to Alexa Fluor 568 (red emission). DRAQ5 (pseudocolored cyan) was employed as a nuclear counterstain. Images were recorded with a 40x oil immersion objective using a zoom factor of 1.6 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.