The War of the Soups and the Sparks: The Discovery of Neurotransmitters and the Dispute over How Nerves Communicate (review)

The elucidation of how nerves transmit chemically is one of the foundational advances in neuroscience, since it helps to explain the workings of brain, muscle, and nerve in terms broadly understood. The scientific basis for this story has already been told by Joseph D. Robinson through elegant enumeration of the sequence of key experiments, in his superb book Mechanisms of Synaptic Transmission: Bridging the Gaps (1890–1990) (2001). Elliot Valenstein now addresses the human side of the story. Three great investigators dominate this account: Otto Loewi, Henry Dale, and Walter Cannon. The unfolding narrative brings out the tension between the electrically based view, championed by physiologists, and the chemical view, which has been linked to the emergence of pharmacology as an academic discipline. The resolution of this question starts with an event worthy of Freudian and Jungian narratives: the handwritten outline of an experiment revealed in successive dreams to Otto Loewi, a physician investigator with a background in the liberal arts. Embedded in Loewi's dream was the insight that a chemical basis for impulse conduction could be tested in the denervated frog heart beating in a physiological salt solution. A first attempt to read his own nocturnal scribble failed, but the second occurrence of this remarkable dream impelled him to run to the laboratory and conduct the experiment, the results of which were published in a very short time.

Before Loewi's famous study, Henry Dale had established his preeminence as a painstaking executant of meticulous laboratory work. Such was Dale's reputation that his detailed letter nominating Loewi for the Nobel Prize in Physiology and Medicine prompted the committee to make a joint award to both Loewi and Dale. Later, Dale regretted that Walter Cannon had not received the prize, due to his published skepticism about chemical conduction which detracted from the other great contributions that Dale and his colleagues admired him for.

Both Dale and Cannon reacted vigorously, and with positive effect, to the Nazi persecution of Jewish scientists. Hitler recognized neither the Nobel Prize nor its German laureates, and Otto Loewi was only one of many who fled after first being attacked and imprisoned by Nazi storm troopers; Valenstein relates how Dale and Cannon made every effort to place and support them. These generous acts helped tilt the axis of contemporary scientific discovery toward England and the United States. The liberalism and decency of people like Sir Henry Dale during history's ugliest decade has made a great scientific story rich in human content. Valenstein tells it with admiration and affection, and in language accessible to the broad readership this book deserves. His portrait of Cannon shows him not only as the equal of his great contemporaries, but also as a great force in American medical education and a philanthropist generous with his service, money, and time to great causes. Like Madame Curie before him, he suffered the delayed effects of radiation, to which he was exposed at a time when science was longer on intellectual adventure than on physical safety.

In its historical review of the chemical basis of nerve conduction, this book lays the basis for understanding how neurochemistry, aided by advances in microscopy, opened the doors to understanding how neurotransmitters work—and of course, to their subsequent pharmacological exploitation, in "the era of Prozac." The author also discusses the value of studying the history of science, including the role of individuals and even their personalities. By contrasting the ever-careful Dale, who came close to discovering chemical neurotransmitters in 1914, with the more speculatively inclined Loewi, Valenstein reminds us that biographical inquiry has a place in elucidating the mechanism of scientific advancement, and that the gifted and tenacious individuals who shape it are more than "straws in the wind of history."