The Initiative on Neurosciences (IONs)

Many tasks, especially those associated with movement and navigation, require the manipulation of vectors.  I will describe collaborative work with Gaby Maimon and Cheng Lyu explaining how the Drosophila brain performs vector computations.  Specifically, experimental work in this collaboration has revealed neural representations of the direction that a fly is traveling in reference to external cues, such as the sun. These representations, which differ from previously characterized heading direction signals, allow the fly to keep track of its motion even when it drifts in a cross wind. Using both experimental results and modeling, we show in detail how the world-referenced traveling direction is computed by a neural circuit that rotates, scales, and adds vectors. This provides a detailed understanding of basic mechanisms needed for goal-directed navigation and path integration.