Project Background
Limb amputations are becoming more common each year, especially lower-limb amputation, largely due to the rise of diabetes and its complications. A limb amputation is an extreme surgery, where the bones, muscles, and nerves are cut in order to remove part of the limb. The cutting of a nerve can lead to changes in the wider nervous system, including the brain and spinal cord. After amputation, nearly all people experience sensations and pain from their missing limb. These are called phantom sensations and phantom limb pain. These sensations and pain can be severe and even debilitating. Previous theories suggest that phantom limb pain corresponds to an increase in excitability of the nervous system. In other words, the nervous system is primed for pain, and sensations that are normally not painful are perceived as painful. We measure spinal excitability using reflexes, which are elicited using electrical stimulation of the nerves and recorded from the muscles in the legs. We recently showed in 3 people with limb amputation that, contrary to current theories, the spinal cord is actually less excitable, meaning that it barely responds or does not respond to attempts to activate its nerves. The goal of the proposed research is to use reflexes to infer spinal excitability following lower-limb amputation, at different times after amputation. We seek to track how quickly the spinal cord changes after amputation. This will tell us when it could be an optimal time to intervene with a treatment, such as a neurotechnology, to stop the changes in the spinal cord.
Student Role
Student Learning Outcomes and Benefits
Ashely Dalrymple
As a mentor, I strive to balance hands-on guidance and facilitating independence so that students can become confident and competent in their research skills and knowledge. When a student first joins the lab, I like to have a one-on-one meeting with them to discuss goals for the term, as well as long-term goals. I believe it’s important to set mutual expectations of each other for the time they are in the lab. I also believe that undergraduate research is meant to build skills. We have tutorials in the lab for processing data, creating figures, and using machine learning. These are meant to provide students with important and widely applicable skills. We are a relatively new lab (Spring 2023) but have a solid team that includes 2 research associates, 3 PhD students, 1 MSc student, and 4 undergraduate students. To date, our undergraduate students have contributed to 3 first-authored conference abstracts, 4 co-authored conference abstracts, received $3,900 in salary and travel grant funding. We believe in providing opportunities for our hardworking undergraduate students so that they can be as successful as possible in their next endeavors. As an undergraduate student in the NERVES Lab, students can expect: • One-on-one meetings with me to discuss your research interests, goals for the program, broader goals, and action items to reach your goals • Project group meetings to present research updates and receive help from myself and other students working on related projects • Lab meetings where we take turns presenting interesting papers, giving tutorials, or practicing presentations • Honest and constructive feedback • Close mentorship from a graduate student • Support to complete the requirements of the SPUR program.