Reduced silverware methods24 appear to show this shortcoming, and in the spinal cord and many other parts of the brain stem, synapse views depended more on reduced silver methods than on Golgi methods (Figures 4-6). These spots succeeded Schultze`s silver staining and were developed at a later stage in the history of teaching neurons by Cajal (1903) and Bielchevsky (1904) on the basis of current photographic processes. There are many types of reduced money methods. Some are suitable for the coloring of the block followed by a cut and others for the coloring of free float sections. In general, they do not color the entire neuronal cytoplasm, but show only a few of the cytoskeleton elements in cells and their processes. That is, they selectively show the neurofibrils25 of nerve cells, and in axon terminals, we often see, but far from being without exception, bundles of fibrils that form rings or dense keulen-like structures in axon terminals (Figures 5 and 6).6). The representation of this Cajal cytoscule element in foam fibers and granulcellular dddriades is illustrated in Figure 4. With regard to this figure, Cajal clearly described the gaps between the sparkling fiber terminals and the dendrites of the grain cells. He compared these gaps to windows or buttonholes and pointed out that these gaps are never visible in Golgi preparations, where the two processes are closely related and form “axosendritic connections through interconnectation.” In other words, in a Golgi preparation, as shown above, if a foamy axon and its ddrist of post-synaptic granulated cells are both colored, both appear to be continuous. The conclusion that they are not continuous was based on the selectivity of the Golgi product and the discontinuity of their cytoskeleton elements. There is little need to point out that the doctrine of neurons has not been accepted without resistance.

The struggle between those who supported the doctrine of neurons, the “neuronists” and the “reluctant” who opposed it, was violent and long, for several decades. To understand the often stormy nature of the argument, it is important to recognize that the debate took place at a time when humanity`s relationship with other organisms was being challenged by scientific conclusions that were the subject of widespread public debate. Among the scientific questions were cellular theory (swan 1838), which claimed a common structure for plants and animals, and the theory of evolution (Darwin 1859) for biology in general. The theories of brain localization (1860s and 18704) and the doctrine of neurons (of Waldeyer-Hartz in 1891) were also directly relevant to the brain in particular. Each of them concerned either man`s relationship with other species or the related subject: the nature of the mind. Everyone has given the beginning of a reductionist analysis of fields long considered the province of unknown theologians of science. That is, there has been a controversy between a reductive view of the brain on the one hand and a holistic, often mystical, view on the other. Although these “deeper” concerns often remain completely silent in the scientific literature, it is impossible to avoid a sense of their presence in violent conflicts. Another question deserves reflection. Can we consider the doctrine of neurons as “one of the great ideas of modern thought” (Shepherd, 1991), comparable to quantum theory, the periodic table or the theory of evolution? I guess in the long run, it is simply considered the cellular theory applied to neurons, which must necessarily be as generous as cell theory to allow cell fusions, extracellular materials, subcellular units of function, etc. The original version of neuron teaching was stronger and stricter than cellular theory and was presented as a “doctrine” to offer a clear and practical reductist approach to the study of neural connections. .

. . .

Share This