Pain is a protective sensation that alerts us to noxious insults and forces us to rest following injury to prevent further damage and expedite healing. Pain is felt most intensely shortly following injury, such as twisting an ankle while playing sports or burning a hand over a stovetop. Initial pain will typically subside within days to weeks following a painful insult. Unfortunately, for over one million Americans their acute pain will develop into a persistent chronic pain where individuals can suffer for years. This becomes even more debilitating for these patients when considering the very limited arsenal of chronic pain treatments. Why some painful insults become long lasting or why some individuals are more susceptible to sustaining chronic pain is unknown. Therefore, there is a huge need for us to increase our knowledge about how pain is generated, so that we can ultimately design more safe and targeted pain treatment options.
Pain is sensed by primary sensory neurons (termed nociceptors) that send one axonal process to the skin and another process to the spinal cord. From the spinal cord pain messages are sent to higher brain regions that interpret the signals, and thus ultimately elicit a sensation of pain. Different kinds of pain such as thermal, mechanical, or chemical pain are sensed by unique molecular classes of nociceptors. In addition, different somatosensory modalities such as itch or touch, are also sensed by specific classes of peripheral sensory neurons. Of our five main sensory modalities vision is the most well understood at the molecular level while somatosensation (touch, pain, itch, temperature) lags significantly behind as compared the others. This degree of unchartered territory provides ample room to make a huge impact in understanding how we process somatosensory stimuli. To learn more about how the Abdus-Saboor lab is addressing the question of how the nervous system encodes pain versus itch versus touch, see the Research section.
Department of Biology
University of Pennsylvania