At the microscopic scale, we do not yet have a good understanding of how biological mechanical sensory organs work. Small aquatic animals make very fast responses to local water movements, which can produce whole-animal behavior including feeding, reproductive movements, or escape from predators within milliseconds. Despite the need for very short response latency, each of these different behaviors requires sufficient information on identity and localization of the source of signals to produce an ecologically appropriate response. This project uses the tiny marine crustaceans called copepods to analyze how their microscopic hairlike sensors called setae are stimulated by small water motions, and how the nervous system controls their extremely rapid specific behavioral responses. Coupling modern high-speed video imaging technology with neurophysiological recording and novel micromechanical stimulation techniques, experiments examine how particular kinds of hydrodynamic fluid disturbance drive movements of the setae, and how neural signals from the setae are encoded to initiate appropriate behavioral responses. Results from this study will have an impact beyond sensory neurobiology to engineering of microsensor technology and robotics, and also to biological oceanography because copepods are a very important component of many marine ecosystems. The project has career and educational impacts by launching a new investigator's research program, and by providing cross-disciplinary student training involving computational, engineering, biological and behavioral approaches to an integrative question.
