Mapping the Distribution of Neuropeptides Typically Involved in Pain-Like Responses in an Insect Model of Nociception
Gurleen Kaur, Angus Hamilton, Sathya Correa
Department of Biology
Faculty Supervisor: Megumi Fuse
Over 20% of the population suffers from chronic pain, but there are few effective models to study its causes. Manduca sexta is a promising model for nociception (a pain-like response) with a highly reproducible defensive strike as a proxy for pain. Its well mapped nervous system should allow us to look for novel compounds that might play roles in nociception in order to create a model for future research. Many neuropeptides have been suggested to have roles in nociception, including Leucokinin (LK) and Diuretic Hormone (DH) in insects. Similarly NO, through the 2nd messenger cGMP, has been shown to impact nociception in vertebrates and invertebrates. Our aim is to use pre-existing data from the lab to map out the locations of LK, DH, and the 2nd messenger cGMP in the nervous system of M. sexta. We used larval nervous systems that were previously stained with antibodies for LK, DH, and cGMP to map out their distribution. Using a light microscope, cell bodies and axons in insect ganglia were identified and the most typically stained regions were described. By using these maps, we can develop hypotheses for the roles of LK, DH and cGMP in nociception, including testing them using the available “pain” assays in M. sexta.