Fireflies emit bioluminescent light signals for visual communication. Since the light emitted is dim, the visual system of fireflies offers a model for investigating how to optimize detection of low-intensity optical signals. Work to date has allowed proposing an optimization model for the colors of firefly bioluminescence, based largely on the sensitivity of the eyes of different species for light of different colors, or spectral sensitivity. This project will investigate how some neurophysiological mechanisms can optimize functioning in ecological settings called "photic niches" at times related to ambient light levels, such as dusk versus late night. Studies will examine if visual sensitivity and flashing rhythm may change with time of day, if the spectral sensitivity of the photoreceptors is different in different parts of the compound eye, and what particular role the different photopigments in the cells of the eye play in modifying the photoreceptor responses. This project is a model multidisciplinary approach to understanding how a sensory system has become adapted in response to evolutionary selection pressure on both the signalling system and the receiver. Results will bear on ecological and evolutionary biology, on insect science and animal behavior, as well as neuroscience. The research environment will provide excellent opportunities for training students, particularly minorities, in current neuroscience.
