Improved rapid method to check electrode localizations in the brain.

A modification of known rapid methods to check electrode localization in the brain is described: the essential point consists in immersing the brain, after fixation in 4 percent Formalin, in pure heptane at -30 degrees C for 5 hr. Unstained sections, cut with the freezing microtome, are placed uncovered on glass slides and photographed (in an enlarger, as if they were negatives) either wet, to obtain a contrast resembling Weil staining, or dry, to obtain a picture corresponding to Nissl staining.