FIGURE 2.

Brain modulation via electrical stimulation of auricular vagus nerve (aVN) endings. (A) Intact feedback-loop which is composed out of efferent VN fibers (controlling different organs and functions) and afferent VN fibers (carrying sensory information back to the brain) for proper control of bodily organs and functions. (B) Different diseases may lead to a lost or impaired afferent feedback to the brain (e.g., due to neurodegeneration or maladaptive plasticity), which makes it impossible for the brain (the control station of the body) to adapt to changes in organs, functions, and/or environmental factors. (C) As a hypothesis, stimulation of aVN fibers substitutes the lost or impaired afferent feedback to the brain while inducing systemic regeneration processes. These processes, in turn, may lead to sustainable recovery of controlled organs and functions as well as recovery of the relevant sensory feedback-loop.