[Centennial of the nobel prize for Golgi and Cajal--founding of modern neuroscience and irony of discovery].

In 1906, Golgi and Ramón y Cajal shared the Nobel Prize in Physiology or Medicine "in recognition of their work on the structure of the nervous system". However, it was an unusual occasion in the history of Nobel Prize award because their views on the structure of the nervous system were not only different but even opposite, creating the "storm center of histological controversy". Furthermore, the new staining method Cajal had employed to study the nervous system was developed by Golgi, creating an irony of discovery. In 1873, Golgi revolutionized the histological study of the nervous system by developing a new staining method, "la reazione nera" or black reaction, which allowed good visualization of axons, dendrites and glia. But because his stain was so selective, staining only about 3 percent of neurons, he was unable to see clearly how the neuronal processes ended as they approached other neurons. Consequently, he embraced the popular belief that neuronal processes physically fuse with each other--the "reticular theory". On the other hand, Cajal was incidentally introduced to the Golgi stain 14 years after its discovery and immediately realized its beauty. He found that better results could be produced by staining more intensely and cutting thicker sections. He further observed that the Golgi stain worked best on non-myelinated axons. The search for brains containing non-myelinated axons led him to study birds and very young mammals, including embryos. Cajal obtained fascinating results by modifying the Golgi stain and by studying avian and young mammalian brains. From those studies, Cajal was able to infer that axons and dendrites ended freely and did not physically anastomose. Therefore, he strongly advocated the "neuron theory". Golgi seemed to be too headstrong and too conservative to relinquish his belief that neurons constitute a network which reacts as a whole. On the other hand, Cajal's hard work using the Golgi stain led to new understanding on the structure and function of the nervous system, and earned him "the founder of modern neuroscience". This centennial occasion may be further impressed by Cajal's comment on the shared Nobel Prize that "what a cruel irony of fate of pair, like Siamese twins united by the shoulders, scientific adversaries of such contrasting character!".