21 May 2010

Some think Cajal made the most significant contribution to neuroscience. Do you?

I was invited to give the Reynolds Lecture at the Reynolds Historical Library at the University of Alabama yesterday. While I was there, I happened upon the English translation of Cajal's Degeneration and Regeneration of the Nervous System. I have had arguments with many neuroscientists and neurologists regarding that Age old-question: which neuroscientist mattered the most? The Neuro Times, of course, has no official opinion, but it seems appropriate to record that the consensus among many neurologists and neuroscientists today is that Cajal mattered the most. That observation, perhaps, says more about our reductionist times than it does about Cajal's actual contributions. Yet Degeneration and Regeneration is a fascinating two volume collection. The preface below gives a sense of the volume. Out of curiosity: does anyone know what Cajal's connection to Argentina was? and how it was maintained?

Author’s Preface to the English Edition

This book may be considered, without exaggeration, as unpublished in Europe and North America. Although there appeared, in 1913 and 1914, a Spanish edition which was paid for by the physicians of the Argentine Republic, nearly all the copies were distributed to the South American subscribers. We were getting ready to send the few remaining copies to those European scientists who have specialized in this type of study, when there broke out the dreadful World War which almost completely prevented any scientific interchanges. It is, therefore, not to be wondered at that there are so very few investigators outside Spain who are aware of the existence of this book. The fact that it was written in Spanish, a language rarely known by scientists, is another reason why it is little known.

The present English translation has saved my work from an irremediable loss. To be worthy of the honour of an edition in the land of Waller, the brilliant initiator of these studies, I have attempted to better the text, and to supplement it with some additions which would have been more extensive and detailed had I not feared to add unduly to an already extensive work, which represents to result of eight years of continuous and patient study.

While there exists in any biological investigation a subjective factor which it is difficult to eliminate, a factor which is equivalent to the personal equation of the astronomers, I have tried to reduce it to the minimum. To do this I have used for my illustrations only preparations that were transparent, strongly and selectively stained, and moderately thick sections. These alone areappropriate for following the regenerated nerve fibres, which are hardly ever rectilinear.

In order to keep down the number of figures without infringing upon their usefulness, I have used the well-known method of combined images. Thus all the degenerated or regenerated nerve fibres depicted in some of the figures are faithfully reproduced from the original specimens, the only artifice employed being the fusion into a single plane of structures taken from two or three successive section of the object.

While we grant to the facts which are revealed by highly selective methods an unquestionable objective value, we do not extend this confidence to any hypotheses, our own or those of other investigators, no matter how seductive they may appear. Indeed, unpleasant though it be to acknowledge, one has to admit that in biology theories are fragile and ephemeral constructions that are renewed every eight or ten years. Even during this brief lapse of time they never attain unanimous scientific approval. Owing this relative agnosticism concerning theoretical speculations I present only the theory of neurotrophism and similar ideas, which the reader will find expounded merely as working hypotheses, useful for the synthesis of facts and acceptable merely as scientific tools in Weismann’s sense. I thus recognize fully that the idea of neurotropism through excitatory chemical actions could be replaced by any other conception, such for example, as the electrical hypotheses of Strasser, Kappers, or by those of Harrison, Marinesco, and other investigators. At any rate, while hypotheses pass by, facts remain. These constitute the only pasting patrimony of the investigator and the only positive addition to scientific progress.

I conclude by expressing my profound gratitude to my very learned friend and colleague, Dr Raoul M. May, for undertaking and carrying through the English translation. I am also very grateful to Sir Charles Sherrington, who has interested himself in the publication of this translation, and to the Oxford University Press who have produced with the proverbial care and elegance of English scientific publications.

S. Ramon Y Cajal

Madrid, September 16th, 1927
Santiago Ramone Cajal, Degeneration and Regeneration of the Nervous System, translated and edited by Raoul M. May, 2 volumes (London Humphrey Milford, Oxford University Press, 1928), v-vi.


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