Neural Basis of Visual Behavior of Limulus

Suny, Upstate Medical University, Syracuse NY

Investigators

Abstract

How do we see? This simple question does not have a simple answer. Vision is a complex process that begins with the absorption of light by the eye and ends with behavior such as perception and locomotion. Because of the complex nature of the vertebrate visual system, especially that of primates, this project uses the relatively simple visual system of the horseshoe crab, Limulus polyphemus. Recent work has uncovered the nature of the neural code for mate detection by this animal during the day, as the eye is "neurally tuned" for this important task. This work will now be extended by a combined anatomical, behavioural, and physiological study of neural coding in the eye and brain with emphasis on understanding how the animal can see so well at night, when light levels are a millionfold lower than in the day. The animal's visual performance in its natural habitat (ocean) will be precisely measured in day and night. The project will quantify the neural information the eye sends to the brain when the animal sees in its natural habitat and then analyze how the brain processes the information it receives from the eye. New behavioural and physiological techniques developed under NSF support together with a wealth of information about Limulus vision establish the animal as an excellent model for studying the link between neural coding and behaviour. Past studies with Limulus have provided milestones in vision research. The proposed studies should prove equally productive. They should reveal concepts of neural coding and behaviour common to other animals and contribute to our understanding of how sensory signals relate to behaviour. In addition, there are outstanding opportunities for undergraduate participation in this multidisciplinary research.