The unending fascination with the Golgi method

Abstract

Introduction\rIn the second half of the 19th century,\rCamillo Golgi provided a breakthrough\rstaining technique for visualising\rwhole neurons, which are seen as black\rbodies due to intracellular staining\rwith microcrystalline silver chromate.\rThe high contrast, selective staining\rproperties enabled identification of\rcomplete neuronal morphology. This\rstaining technique, termed the Golgi\rmethod, was later improved by Ramón\ry Cajal and popularised through his\rtireless experiments. Morphological\ranalysis, using the Golgi method, led to\rthe discovery of neuronal microstructures\rsuch as dendritic spines and\rgrowth cones and helped give rise to\rthe ‘neuron doctrine’. Many post-mortem\rhuman brains as well as brains of\rexperimental animals have since been\rstained using this method. In combination\rwith other morphological\rtechniques (e.g. electron microscopy\rand immunohistochemistry), the Golgi\rmethod has allowed us to glean more\rinformation regarding the neuronal\rnetworks present in various brain regions.\rHowever, the Golgi method is a\rdifficult first choice for morphological\ranalysis since it is capricious, complicated\rand time-consuming and has\rpoor reproducibility.\rRecent increases in the number of\rin vivo animal experiments and of\rpost-mortem brains collected following\rneurological disorders heighten\rthe need for the Golgi method to be\rviewed as a crucial morphological\rtool for assessing abnormalities in\rsingle neurons, as well as in neuronal\rnetworks. Fortunately, over 100\ryears of neuroanatomical diligence\rhas seen significant contributions\rto overcoming the shortfalls of this\rmethod. The advent of modified Golgi\rmethods with potential use as routine\rtechniques, together with the development\rof the kit-based Golgi–Cox\rmethod, has made the Golgi method\rmore accessible to neuroanatomists.\rThis review surveys the technical\rfundamentals, history and evolution\rof Golgi methods and intends to\rspark an interest in the Golgi method\rwithin every neuroscientist, novice\rand old pro alike and to allow them\rto appreciate this useful technique.\rConclusion\rMany neuroanatomists, including us,\rfeel a strong attraction to the Golgi\rmethod as a powerful morphological\rtool. Our researchers have identified\runwanted issues of the various Golgi\rmethods and then have been working\rto remedy these problems. We\rencourage the reader to adopt staining\rusing the Golgi method as its utility\rcontinues to evolve.