QUANTITATIVE ANALYSIS OF CEREBRAL CORTEX .I. ASELECTIVITY OF GOLGI-COX STAINING TECHNIQUE

The aim of these investigations is to give quantitative descriptions of a number of neuronal parameters in the cerebral cortex of the rabbit as a function of depth below the pial surface. Such investigations are committed to the use of a Golgi staining method. Since these methods only stain a small percentage of the neurons thick sections (80-120 μ) can be studied, which allow us to obtain sufficient information about the spatial distribution of the dendrites. The use of a Golgi method, however, introduced a number of methodological difficulties, and these are discussed in this first paper of a series. An uncurved part of the striata area of the rabbit was used. Two groups of measurements were made. 1. 1. In sections cut at 80 μ perpendicular to the pial surface and stained according to the Golgi-Cox method, all stained neurons present in a certain column were analyzed. The measured values were: depth below the pia, cell body volume and number and distribution of dendrites. The measurements were carried out in 5 rabbits. 2. 2. In sections cut at 40 μ perpendicular to the pial surface and stained according to the combined Golgi-Cox/Nissl staining procedure14, of all neurons present in a certain column depth, cell body volume and nuclear volume were measured. These measurements were made in a 6th rabbit. The site of analysis was located in reference to the corpus callosum and the fissura sagittalis lateralis. To investigate the homogeneity of the material, the observations were arranged in a classification scheme not only based on the depth, but also on other, necessarily introduced, factors such as e.g. the different rabbits. The influence of these factors was investigated by statistical techniques. It was concluded that the method for the localization of homologous sites had been sufficiently accurate and that in our standardized design of the experiment the systematic differences were small. Approximately 1% of the neurons had been stained by the Golgi-Cox-staining method. A good agreement existed between the cell body volume of the Golgi-Cox-stained neurons and the cell body volume of the Nissl-stained neurons. We concluded that the Golgi-Cox material can be considered as an adequate sample. © 1969.