VIP and neuropathic pain: For example, neuropathic pain is associated with an increased activity of PV+ interneurons and a reduced activity of SSt+ interneurons and vasoactive intestinal peptide (VIP)-expressing interneurons in the medial prefrontal cortex [10–12], whereas activation of SSt+ interneurons in the somatosensory cortex prevents the development of neuropathic pain [13].