Myelinated Fibers and Saltatory Conduction in the Shrimp

by Xu, Ke; Terakawa, Susumu

• ISBN13: 9784431539230
• ISBN10: 4431539239
• Edition: 1st
• Format: Hardcover
• Copyright: 2013-10-29
• Publisher: Springer Verlag

Summary

The book we propose will describe the origin and mechanisms of nerve impulse conduction in the shrimp. Surprisingly, the conduction velocity in shrimp nerve is the fastest among all nerve fibers in the animal kingdom. One of the authors (K.X.) originally found this in 1955 in Tsingtao, China for the first time in the world. There are many reasons for this fastest velocity. We investigated them during the last quarter of the previous century and solved the all physiological questions related to this problem. The enigma of shrimp is experimentally dissolved and the evolutionary position of shrimp is compared to those of well known nerve fibers in vertebrates. Use of the advanced light microscopy in combination with the difficult electrophysiology showed an unusual figure of excitable patch of axonal membrane which is developed with unusual wrapping with myelinations. Our discovery of this structure shows extremely clever method of achieving the fastest impulse conduction using lipid, proteins, and ions. The physiological mechanism is the result of an evolutionary miracle, or beyond-imagination wisdom of the God. It is very interesting from biological point of view, and also from clinical point of view, because it is known that the unmyelination by some disease mechanism causes paralysis in humans. The shrimp nerve has a very unique myelination which would suggests an alternative way to make myelinations for treatment of the human disease. The saltatory conduction was first described in frog nerve by Dr. Ichiji Tasaki (who is now 98-year old investigator at NIH, USA, and was a mentor to one of the authors, S.T.) in 1939. It is now about the time to give a comprehensive view to the saltatory conduction as a means to achieve the fast nerve impulse, at this time when almost all mechanisms in different species have been completely elucidated.