Fig. 1.

Dual action of VNS. Stimulation of the vagus nerve at the cervical level drives nerve action potentials to activate afferent projections to CNS neuromodulatory centers (top) in conjunction with activation of parasympathetic efferent fibers (bottom). This unique dual action of VNS provides both a neural plasticity-reinforcing stimulus through afferent activation and a calming parasympathetic input through efferent activation