P2RX2 and irritable bowel syndrome: Especially, P2X3 receptors play an important role in mediating the occurrence and maintenance of pain in neurons of the intestinal myenteric plexus, dorsal root ganglia (DRG), spinal dorsal horn, prefrontal cortex, and anterior cingulate cortex in a rat model of IBS with visceral hypersensitivity [14], and acupuncture can achieve visceral pain relief through purinergic receptors at different levels of the brain-gut axis.