"Nerve terminals release chemicals" release chemicals" ? discovered by:

D i.e. Loewi Otto Loewi discovered that nerve terminals or synapse release chemicals. In his most famous experiment, Loewi took fluid from one frog hea and applied it to another, slowing the second hea and showing that synaptic signaling used chemical messengers. Before Loewi's experiments, it was unclear whether signalling across the synapse was bioelectrical or chemical. Loewi's famous experiment, published in 1921, largely answered this question. He dissected out of frogs two beating heas: one with the vagus nerve which controls hea rate attached, the other hea on its own. Both heas were bathed in a saline solution (i.e. Ringer's solution). By electrically stimulating the vagus nerve, Loewi made the first hea beat slower. Then, Loewi took some of the liquid bathing the first hea and applied it to the second hea. The application of the liquid made the second hea also beat slower, proving that some soluble chemical released by the vagus nerve was controlling the hea rate. He called the unknown chemical Vagusstoff. It was later found that this chemical corresponded to Acetylcholine