So let’s say you are boiling a pot of water on the stove to prepare yourself a delicious pasta dinner. Once the pasta is cooked, you go to strain it in the sink. Now, for the purpose of this story let’s imagine that you are a klutz (God knows I am), and a bit of the water splashes back and burns your finger! Ouch! What do many of us do next? We suck on our finger of course! But why is this often the go-to move in response to a painful insult? Today we are going to break down how our body “gates” pain!
The reduction and elimination of pain has been an enduring feature in the zeitgeist of neurological research. Our understanding of pain changed dramatically in 1965 when Melzack & Wall published their seminal paper on “Pain-gating.” This new theory synthesized the work of several other researchers to explain the mechanism by which pain is attenuated when you rub (or in the case of our burn example, suck) the skin near the site of injury (Melzack & Wall, 1965).
As we spoke about in “Ouch! The Not So Universal Experience Of Pain,” pain signals are sent by nociceptive (pain-sensing) nerves called Alpha-Delta fibers and C fibers. The AD and C fibers send their pain signals to nerve cells in a portion of the spinal cord called the “Substantia Gelatinosa.” The neurons in the substantia gelatinosa send their signal up to the brain to process and generate the conscious experience of pain (Meldrum & Liebeskind, 2021). The Pain-Gating theory of pain proposes that nerves that carry information on physical sensation (like touch and pressure) are able to decrease the AD & C fibers signaling to the substantia gelatinosa. This allows the co-occurence of touch in areas adjacent to pain to reduce the intensity of the pain signals sent to your brain (Mendell, 2013).
The ability for your touch-sensitive neurons to “gate” the pain signals your brain receives has been crucial in the development of new therapeutic techniques to reduce chronic pain (Katz & Rosenbloom, 2015). Research on pain has come a long way since 1965, but Melzack and Wall’s contributions have stood the test of time. Whether you are struggling with the acute pain of burning your finger or the chronic pain of arthritis, know that researchers are working around the clock on improving our ability to treat it. By learning the underlying mechanisms that produce pain we can all work together toward a pain free future.