HTR5A and neuropathic pain: It also plays a critical role in opiate-induced antinociception, probably through activation of descending inhibition (86, 87).The administration of systemic antidepressants such as selective serotonin reuptake inhibitors (SSRIs) can increase the concentration of 5-HT in the spinal cord, producing anti-hypersensitive effects in rodent models of neuropathic pain (88).