Speaker: Lauren Walker, PhD. Assistant Professor Molecular and Systems Biology, Geisel School of Medicine at Dartmouth College
91¸£Àû the speaker: Lauren has always been fascinated with how we build, maintain, and regenerate complex structures like the nervous system. She studied degeneration as a PhD student at Washington University in St. Louis with Aaron DiAntonio and then switched to regeneration during her postdoc with Michael Granato at the University of Pennsylvania. She established her lab in 2024 at Dartmouth, where they use a zebrafish model to study how motor neurons find their correct muscle targets to enable coordinated movement. More recently, they have expanded their focus to tissue regeneration. They use a combination of genetics, molecular biology, live imaging, and transcriptomics to understand how the cells and signals that drive functional regeneration.
91¸£Àû the Seminar: Humans are poor regenerators: injured nerves frequently reconnect to incorrect targets, and limb regeneration is limited to the fingertip. Achieving accurate, faithful regrowth of complex tissue remains a central unsolved problem in regenerative biology. We address this using the larval zebrafish pectoral fin, a transparent, regenerating vertebrate appendage developmentally homologous to the tetrapod forelimb. We employ two complementary injury paradigms: laser-mediated transection of only motor axons and full amputation of the fin. In both cases, functional regeneration is complete within days, giving us a window into nerve and tissue regrowth. This system allows us a unified set of questions: how does the nervous system regenerate, how does a tissue regenerate, and how does the nervous system regenerate within a tissue that is itself still regenerating? Using transgenic labeling of individual cell types, we employ longitudinal live imaging to observe cell interactions and compare motor axon targeting over time, across development, isolated nerve injury, and whole-appendage regeneration. Across these contexts we find that axons are strongly biased toward reinnervating their correct original targets, but that the degree to which they make, and ultimately correct, errors differs between contexts. By comparing development, injury, and regeneration within a single model, we are working to identify the injury conditions and molecular mechanisms that determine accurate versus aberrant innervation as tissue and nerve regenerate together.
Please join us for this in person event in 107 Norman Smith Hall.
