Electrophysiological characteristics of aortic baroreceptors

Myelinated and unmyelinated fibers with conduction velocities of 12–30 and 0.9–1.2 m/sec respectively were identified in the left aortic nerve in rabbits. In experiments on an isolated preparation of the aortic arch the electrophysiological characteristics of the aortic baroreceptors with myelinated and unmyelinated fibers were studied by selectively blocking conduction in these fibers. Baroreceptors with unmyelinated fibers were shown to have a higher threshold pressure and a wider range of function.