A modified Da Fano silver stain for demonstration of neurons and dendrites in glycol methacrylate-embedded brain tissue.

Golgi impregnation techniques are commonly used for characterization of neurons and their dendritic and axonal processes. Most of the widely used techniques require processing of fresh brain tissues, which limits the amount of material available for study. Additionally, the stained blocks must be subsequently embedded in paraffin, which produces considerable cellular shrinkage and distortion artifacts. Modification by one investigator of an early silver impregnation technique, designed to demonstrate the Golgi apparatus, allowed demonstration of neurons and their dendritic processes. Our further modification of the later technique, along with embedding of the stained tissue in glycol methacrylate, permits detailed examination of neurons and their processes in formaldehyde-fixed neonatal human brains. In cerebellar sections, this modified technique impregnates nearly all Purkinje cells, elucidating the fine structural detail of the developing neuronal dendritic tree and spines.