COMPARATIVE STUDIES OF THE CENTRAL NERVOUS SYSTEM PHOSPHATASES EMPLOYING THE GOMORI AND AZO-DYE METHODS

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Abstract
The histochemical study of the central nervous system alkaline and acid phosphatases is made by comparing the elements demonstrated by the Gomori methods with those revealed by the methods of simultaneous coupling with the azo-dyes. The activating effect of the magnesium ion was especially dealt with in the research on the alkaline phosphatase of the nerve cell nuclei. The material employed consisted of the cerebral and cerebellar cortices, the rhombencephalon and the cervical spinal cord in the rabbit, guinea pig, rat and dog. The results obtained with both types of techniques correspond in certain basic points: positivity of the blood vessels and of the neuropil, regarding the alkaline phosphatase; positivity of the nerve cell bodies, the neuropil and the lipofuscin granules, with regard to the acid phosphatase. They differ, however, in the followining: the azo-dye methods never reveal the nerve cell nuclei; in the case of the acid phosphatase, they uniformly stain the cytoplasm of the perycarion, whereas the Gomori method shows the Nissl substance or the neurofibrils; in the case of the alkaline phosphatase, the azo-dye is the only method which stains the nerve fibres afferent to the cerebellar cortex in the granular layer. The magnesium ion, added in the usual concentration to the alkaline phosphatase Gomori incubating medium and when the Barger variant is used, intensifies the tones; its excess (concentration of 0.16 [image]) even emphasises the tone in the nucleoli, but that of the neuropil is decreased. The use of the azo-dye methods seems a means of correcting certain artefactual excesses of detail present in the images provided by the Gomori methods. The effects produced by the magnesium ion are not proof enough to demonstrate the presence of the alkaline phosphatase activity in the nerve cell nuclei.