Figure 3
Comparison of VNS-dependent recovery in hypersensitive and hyposensitive models of nerve injury. (a) In previous studies, damage to the median and ulnar nerves causes somatosensory hyposensitivity and weakness in the forelimb. Pairing VNS with tactile rehabilitation significantly improves elevated sensory thresholds, restoring them to normal levels. Data from6. Additionally, VNS paired with motor rehabilitation significantly improves forelimb weakness compared to equivalent training without VNS. Data from5. (b) In the present study, injury to the radial nerve in the forelimb causes allodynia and weakness. Pairing VNS with tactile rehabilitation fails to restores somatosensory function. Moreover, VNS paired with motor rehabilitation fails to improve recovery forelimb strength compared to equivalent training without stimulation. The absence of VNS-dependent benefits in either somatosensory and motor recovery after radial nerve injury likely arise due to the chronic pain induced by the injury.
