Muscle function research: PhD student studies ways to preserve movement

Sam Lapp, a PhD candidate at Harvard T.H. Chan School of Public Health, studies how skeletal muscle responds to eating and exercise using mouse models; his work found that blocking insulin-driven protein synthesis did not change muscle size, leading him to focus on contraction and neuromuscular connections.

Sam Lapp is a PhD candidate in the Biological Sciences in Public Health program at Harvard Griffin Graduate School of Arts and Sciences, conducting research in Brendan Manning’s lab at Harvard T.H. Chan School of Public Health. He studies the basic biology of skeletal muscle to better understand how muscles respond to eating and exercise. His path to this work included an early interest in science, undergraduate study in cell and molecular biology, an internship at the Shirley Ryan AbilityLab, and a master’s in kinesiology and community health. Lapp says he is motivated by both curiosity and a desire to help people maintain or recover muscle function. He was diagnosed with relapsing-remitting multiple sclerosis during his PhD and plans to study neuromuscular junctions going forward. Key facts: - Lapp’s research uses mice engineered with a mutation in a muscle protein that prevents some insulin functions, allowing study of insulin’s role in muscle. - His experiments reported that eliminating insulin’s activation of protein synthesis did not change overall muscle size in these models. - That result directs attention toward other stimuli, especially muscle contraction, as important for maintaining or restoring muscle mass. - The work highlights contraction-responsive pathways as potential targets for therapies for immobilization-related atrophy, sarcopenia, and cachexia, as discussed in the article. - Lapp plans to focus future work on the neuromuscular junction because of its role in sustaining movement and its relevance to neuromuscular disorders and possibly multiple sclerosis. Summary: Lapp’s findings suggest that insulin-driven protein synthesis is not the sole determinant of muscle size in his mouse models, pointing researchers toward contraction-responsive pathways and neuromuscular connections as areas of interest. He intends to continue studying how nerves and muscles interact, and to pursue research that could inform ways to preserve or restore muscle function over time.