The architecture of a neuron's dendritic arbor profoundly influences its ability to receive and transmit synaptic information and determine a neuron's role within synaptic circuitry. Elucidating the mechanisms that control dendritic development is therefore fundamental to understanding how individual neurons wire themselves into intricate networks. In the context of the present CAREER award Dr. Lom will use the developing Xenopus laevis retinotectal projection to investigate how both local retinal signals and target-derived tectal signals shape the early morphogenesis of Xenopus retinal ganglion-cell (RGC) dendritic arbors in vivo and in vitro. Dr. Lom will examine how three important dendritic differentiation cues (BDNF, activity, and FGF) transmit arborization signals to developing RGCs. To this end, Dr. Lom will alter local and/or target environments at the onset of dendritic development and visualize RGC dendritic arbors in vivo by retrograde fluorescence labeling and in vitro by immunostaining. Dr. Lom will establish a vibrant developmental neurobiology research and training program at Davidson College. All experimental questions and methods will be fully integrated in an undergraduate research-training program to provide new opportunities for undergraduates to engage in original research. Recognizing that students learn best when they invest themselves in the practice of doing real science, the research delineated in this proposal will provide opportunities for students to conduct extended independent research projects on questions of dendritic development through three programs: full-time summer employment, enrollment in Independent Research course credit, and enrollment in Developmental Neurobiology, a unique research-intensive group-investigation course. Because the benefits of active engagement in scientific research are equally important in the high-school science curriculum, local high-school biology teachers will also be employed in Dr. Lom's laboratory as summer research assistants. By experiencing research first-hand, high-school teachers will be better skilled to incorporate inquiry-based experimentation in their classrooms. The nature of the proposed research encourages teachers to place their data directly into the hands of their students. High-school students will analyze dendritic-arbor morphologies and thereby experience important aspects of the research process. Thus, by establishing a research-training program at Davidson College, both undergraduates and high-school teachers will directly experience the practice of science as they contribute to our understanding factors that shape the development of dendritic arbors.
