Understanding how the brain efficiently extracts relevant information from a complex visual scene, and uses these cues to guide behavior represents a fundamental problem in neuroscience. Despite considerable effort, even compact circuits that implement the elementary visual computations that are the building blocks of brain function remain poorly understood. This project will combine genetic analysis, behavioral studies and microscopy to dissect such circuits. These studies will shed light on the computational mechanisms of the brain. More broadly, this study will engage underrepresented high school students in neuroscience research by developing a new educational program that combines the physics of light with animal behavior in the local environment, developing quantitative analysis skills.
Linear polarization represents a fundamental quality of light that arises naturally from atmospheric scattering, and surface reflections. Many animals orient their movements using these signals, and studies in a variety of insects have developed computational models for how neural circuits might guide behavioral responses to polarized light, models that share key elements with models of color perception. Thus, understanding these circuits provides insight into many important visual processing tasks. This project will investigate the neural circuits that compute responses to polarized light. The first objective of this project is to identify neurons that respond to polarized light signals presented to the ventral retina of the fruit fly Drosophila, using a combination of advanced genetic tools for manipulating neural activity and behavioral studies. The second objective will use in vivo two photon microscopy to measure changes in neural activity induced by polarized light in order to describe the response properties of individual neuron types. The third objective will map the functional connections between neurons in these circuits by simultaneously increasing and decreasing the activities of specific circuit components, while imaging the responses of downstream neuronal targets. This work will determine how the brain processes information about polarized light.