AMMONIACAL SILVER STAINING OF DEGENERATING AXONS

Degenerating axons in the central nervous system can be selectively stained by ammoniacal silver nitrate and citric acid-formalin reducer (after Nauta and Gygax, 1954) alone. This selective staining can be obtained without any type of pretreatment. It has been found that if the tissue sections are treated first with various lipid solvents (e.g. acetone, carbon tetrachloride, chloroform-methanol, etc.) and then stained by ammoniacal silver nitrate and citric acid-formalin reducer, degenerating axons are still selectively stained. These results are discussed in relation to earlier histochemical work on the Nauta and Gygax (1954) and Nauta (1957) methods. © 1969 Springer-Verlag.