The Golgi-Cox Technique

Abstract

At a time when an avalanche of new techniques are being applied to the morphological analysis of the nervous system, it may appear out of place to reconsider the application of one of the oldest metallic stains used in Neurohistology. Nonetheless, the past decade has witnessed a remarkable resurgence of interest in the Golgi methods, a development that may reflect the more or less explicit suspicion that the image provided by these techniques may be, after all, the one that most distinctively characterizes the nervous system, particularly when compared with the histological picture of non-nervous tissues. As is true of all of Histology, the greatest single source of new fundamental information concerning the structure of brain tissue has been the electron microscope. But the great value of combining electron microscopic examination with the analysis of Golgi-stained material has also been proven (Blackstad, 1963; Fox et al, 1967; Pappas et al., 1966). Electron microscopy, for example, has permitted observations concerning details of synaptic relationships that lie well beyond the reach of the Golgi method or any other light-microscopic technique. On the other hand, but for the Golgi method, it is doubtful that a panoramic conceptualization of the nervous system could ever have been attained. It is important to realize that the degree of information provided by any form of microscopy is by no means uniformly proportional to the degree of magnification or resolution provided by the technique. For example, a magnification in the order of several millions, if technically possible, might permit the visualization of the elementary particles of matter: electrons, protons, etc. But it would be ludicrous if, confronted with such pictures, one would draw the conclusion that there is no essential difference between the material structure of the brain and, for example, that of a piece of wood. On the other hand, in view of the fact that the brain can be regarded as a signal-processing structure, one may be tempted to point out its similarities to an electronic apparatus. In that case, one may regard the picture provided by Golgi-stained material as the one which better accounts for that similarity, at least from the morphological point of view. The image of tangled and overlapping neural processes produced by the Golgi method is indeed more reminiscent of electronic wiring than are histological brain pictures provided by any other technique.

This work was supported by the Medical Research Council of Canada and by grant no. DA-49-007-MD-1005 from the U.S.Army Research and Development Command.