Follow the wandering nerve

"This is a bott le of pills," says J.P. Errico, showing me something that???s obviously not a bottle of pills. Errico, who is cofounder and CEO of ElectroCore Medical, is holding the GammaCore, a noninvasive vagus nerve stimulator. If ElectroCore???s R&D work holds up, this device is about to turn decades of evidence about the importance of a single nerve into a new kind of medicine: an electrical therapy as benign as a morning swim and as straightforward as popping a pill with your coffee.