Administration of a selective mGluR8 agonist (DCPG) or mGluR8 PAM (AZ2216052) into the PAG, dorsal striatum or amygdala (CeA) increased thermal (tail flick and plantar test) and mechanical withdrawal thresholds in inflammatory (carrageenan) and neuropathic (SNI) conditions [157,163,169], although intra-PAG administration of DCPG was recently reported to have no effects on thermal hyperalgesia [171] but decreased cold allodynia [172] in a neuropathic pain model (spinal cord contusion). The gene discussed is GRM8; the disease is neuropathic pain.