Which neurotransmitter is specifically linked to pain perception and immune response?

Substance P is a neuropeptide that plays a critical role in pain perception. It is primarily found in the central and peripheral nervous systems and is involved in transmitting pain signals from the site of injury to the brain. When tissues are damaged, Substance P is released, activating pain receptors and signaling the brain that there is an injury.

In addition to its role in pain, Substance P also influences the immune response. It is known to modulate immune cell activity and can facilitate the release of pro-inflammatory mediators, thereby linking pain perception with immune processes. This dual role underscores its importance in conditions involving both pain and inflammation.