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Science and Undergraduates at the Research University

Research Summary

Darcy Kelley's research uses the South African clawed frog, Xenopus laevis, to study the neurobiology of social communication, with the goal of determining how one brain communicates with another. Her HHMI project is a Web-based resource that will make educational materials generated in Frontiers of Science (Columbia's new interdisciplinary core course in science) freely available and will provide a platform for college science teachers to share their own teaching approaches and materials and to consult with their colleagues about educational issues.

Together with David Helfand and other Columbia faculty members, Dr. Kelley developed an interdisciplinary course taken by all Columbia undergraduates: Frontiers of Science. Frontiers combines small seminars and lectures by leading Columbia Scientists to teach students the methods of analysis used across a range of scientific disciplines. The lectures and course materials from an entire semester are feely available online at: http://frontiersofsci.org/

Dr. Kelley has a long-standing interest in the portrayal of science in movies, plays and radio. She consults for the Sloan Foundation Ensemble Studio Theater project and has served on panels at the Tribeca, Sundance, and Hamptons Film festivals.  She served as the model for the amphibian biologist played by Geena Gershon in Claudia Meyer's film, "Kettle of Fish.”

Original Project (2002 grant):  The initial grant supported three projects. The first is a multidisciplinary course, Frontiers in Science, for first-year students at Columbia College. The course is required for all entering students (both "science" and "nonscience" students). The lectures cover some of the great ideas of science, such as dark matter, the origins of the universe and of life, evolution, how the brain works, and the biome. Course-associated materials have been made available to other universities informally. The course also features small seminars, led by postdoctoral teaching fellows, in which topics from the physical and life sciences are discussed. The second project is a course for premed students that uses case studies to teach them about designing, analyzing, and interpreting clinical research. The third project is a research program in my laboratory in which students use clawed frogs (Xenopus) to study gene expression in the vocal system.

Project Update (2006 grant):  We will create a Web resource, Frontiers of Science Online, to disseminate course material we have developed and to create an interactive center for educators in undergraduate science education. One aim of the project is to increase students' interest in science by teaching the most interesting, state-of-the science material first rather than requiring students to first go through a series of preparatory courses before gaining access to current research. Another aim is to increase the visibility and cachet of undergraduate teaching by creating a compelling body of material prepared by top researchers and educators. Materials will include videos of faculty lectures, animations and simulations, question and problem sets, study guides, practice examinations, and an interactive e-textbook, Scientific Habits of Mind, developed by Columbia University faculty. The site will include seminar materials, developed by postdoctoral teaching fellows (Columbia Science Fellows), that correspond to the units taught in the Frontiers in Science course and approximate the learning experience of undergraduates in the course. The Web site will also foster a supportive peer community among educators by enabling them to share new teaching approaches and materials directly with one another.

Research in the Kelley Lab

Research in Darcy Kelley's laboratory focuses on the neurobiology of vocal communication using, Xenopus laevis, the South African clawed frog, as an experimental model system. In their dark, crowded ponds, sound is the primary mode of social communication and is essential for finding and attracting a mate. The importance of vocalizations has shaped a nervous system specialized for detecting acoustic cues that can be used to respond appropriately to potential mates and to rivals.   

Xenopus cannot breathe while calling underwater and they produce sounds simply by contracting their vocal muscles. We used motor nerve stimulation in the isolated larynx to determine how neuromuscular activity and vocal organ tuning control acoustic properties of calls. Because activity on the laryngeal nerve precisely matches actual calls, components of the hindbrain central pattern generator (CPG) have been identified in the isolated brain ex vivo using fictive calling patterns recorded from this nerve. 

Tracing auditory projections from the nerve from the hindbrain to the forebrain led to the Xenopus amygdala (AMY).  The AMY both receives input from the auditory midbrain and projects to the component of the hindbrain vocal pattern generator responsible for determining call patterns and rhythms. Damage to the AMY interferes with a male's ability to recognize acoustic cues conveying sex and reproductive state. We are examining the auditory representation of this information in the AMY with the goal of determining how distinct vocal patterns are generated in response to social cue. Both the forebrain neural elements that initiate signaling and the hindbrain CPG are hormone-responsive and sexually differentiated. The elements that comprise the forebrain and hindbrain circuit elements that we study are highly conserved in molecular features and function from frog (Xenopus) to humans. The isolated central nervous system preparation is a powerful and informative resource for determining how hormones act on neural circuits to produce sex differences in reproductive behaviors. Together with other members of the Sociogenomics Initiative, we will be using a cassette of highly conserved, socially responsive genes to drive neural activity in AMY and determine effects on fictive call patterns in transgenic frogs.

In each Xenopus species, males produce a unique advertisement call distinguished by its temporal pattern and spectral properties. A cross-species analysis of these calls suggests that call types evolved from an ancestral burst pattern, becoming either simpler or more complex. Each advertisement call type occurs in each of the major branches of the phylogenetic tree and probably serves to advertise species identity. Some spectral features, however, are highly conserved within groups of closely related species and may reflect conserved morphological features of their vocal organs.

Last updated May 2014