Through a series of experiments involving the vagus nerves of frogs, Loewi was able to manually slow the heart rate of frogs by controlling the amount of saline solution present around the vagus nerve.
A través dunha serie de experimentos no nervio vago das ras, Loewi puido controlar manualmente o ritmo cardíaco da ra controlando a cantidade de solución salina presente arredor do nervio vago.