Figure 2
Central processing of pruritus.
Pruriceptive primary afferent nerve fibers from the skin activate spinal neurons in lamina I of the dorsal horn, which project to the thalamus. Direct excitatory connections from the thalamus include anterior cingulate cortex (ACC), insular cortex (Insula), and primary and secondary somatosensory cortices (SI, SII). The putative function of brain areas activated in central imaging studies of itch are summarized. SMA, supplementary motor area; PMA, premotor area; PF, prefrontal cortex; OrbitoF, orbitofrontal cortex; PAG, periaqueductal gray.
