66
The Body Electric
stein maintained that, after injury, the damaged ceil membranes simply
leaked their ions out into the environment. Thus the current of injury
was no longer a sign that electricity was central to life, but only an
uninteresting side effect of cell damage.
The vitalists, with their hopes pinned on electricity, kept getting
pushed into tighter and tighter corners as electricity was removed from
one part of the body after another. Their last stand occurred with the
discovery of neurotransmitters. They'd maintained that only an electrical
current could jump across the synapse, the gap between communicating
nerves. In 1920 that idea was disproven with a lovely experiment by
Otto Loewi, a research professor at the NYU School of Medicine, later
my alma mater. When I took physiology in my first year there, we had
to duplicate his experiment.
Biologists had found that a frog heart would continue to beat for
several days when removed with its nerves and placed in an appropriate
solution. Stimulating one of the nerves would slow it down. Like Loewi,
we took one such heart, with nerve attached, and stimulated the nerve,
slowing the beat. We then collected the solution baching that heart and
placed another heart in it. Its beat slowed even though its depressor
nerve hadn't been stimulated. Obviously the nerve slowed the heartbeat
by producing a chemical, which crossed the gap between the nerve end-