The sympathetic nervous system was thought to have evolved with jawed vertebrates. But lampreys—jawless, parasitic fish that suck out the blood of their hosts—have a simple one, per recent research.

With terrifyingly sharp teeth arranged around a circular mouth, lampreys look about as primitive a vertebrate as you could imagine. But a new study finds that the animals have a surprising similarity ...

Researchers have created a digital topographical map of the cardiac sympathetic neural network, the region that controls the body's heart rate and its 'fight-or-flight' response. They hope this map ...