Lab manager Michael Lin at the bench
We have short and long-term projects for undergrads (freshmen to seniors) and Masters students.
The Fuse Lab is focused on understanding how animals respond to external stresses and tissue damage, from a physiological and developmental perspective. We use an insect model, Manduca sexta, to address questions that are fundamentally important for all organisms.
1) How are neurons sensitized after noxious stimuli? M. sexta shows a defensive strike response that becomes sensitized after a noxious stimulus. We are interested in the cellular and molecular processes underlying sensitization of the defensive strike response.
2) What are the systemic responses to tissue damage? We selectively damage the highly proliferating and regenerative imaginal discs by x-ray irradiation, and monitor systemic effects on the nervous, immune and endocrine systems.
Nociceptors are sensory neurons that are activated by injury or inflammation, and this activation is perceived as pain in humans. With persistent insults, the nociceptors become sensitized, often resulting in chronic pain. This is manifest as long-term hyperexcitability and/or spontaneous electrical activity in the nociceptors, and is noted in both vertebrates and invertebrates. This is a form of nociceptive memory that appears to utilize mechanisms similar to those used in inducing other forms of learning and memory. Our lab is interested in the conservation of nociceptive signaling mechanisms between invertebrates and vertebrates and across categories of learning and memory. We use the defensive strike response in the hornworm Manduca sexta as a gauge of nociception. In particular, we are looking at the signals transmitting “pain” information, including analgesia, using both an in vivo bioassay as well as an in vitro electrophysiological preparation.
Systemic responses to imaginal disc damage
Growth requires increases in tissue mass but also coordination between tissues to ensure appropriate body allometry. Regulation depends on both genetic and environmental factors. In holometabolous insects (e.g. flies and moths), regulation of both growth and metamorphosis depends on complex interactions of hormones and other factors from the nervous and endocrine systems as well as from the imaginal discs (stem cell-like adult progenitor tissues). The regenerative imaginal discs can be selectively damaged using x-ray irradiation, because of their high proliferation rates in the last larval instar, and systemic effects can be monitored. We are assessing responses to whole body x-ray irradiation of the hornworm, Manduca sexta. As has been previously noted in Drosophila melanogaster, we note delays in both larval and pupal development, and we are assessing the mechanisms for these delays in terms of endocrine regulation and responses by hemocyte populations.