Synapses
In the nervous system, a synapse is a structure that permits a nerve cell to pass an electrical or chemical signal to another nerve cell. The word comes from the Greek synapsis , which means “conjunction”, and was first employed by the English neurophysiologist Charles Sherrington in 1897. When I arrived in Saint Louis in 1958 and began to spend some afternoons at the Central Institute for the Deaf, Dr. Donald H. Eldredge – a neurophysiologist and also a good friend – told me a story concerning the synapses of the cochlear hair cells. With the advent of the electron microscope in the early 1950s, nerve endings were found to contain a large number of small vesicles. The term synaptic vesicles was given to these structures. He also told me that one of the researchers involved in electron microscopy had a special interest for quantum theory and made some calculations on the size of the vesicles. As predicted by Max Planck, the quantum mechanics are absolutely essential to deal with...