Alexander BORST

Alexander Borst studied Biology at the University of Würzburg where he obtained his PhD under the supervision of Martin Heisenberg. In 1984, he became a postdoctoral fellow at the Max Planck Institute of Biological Cybernetics in Tübingen. From 1993-1999, he led a Junior Research Group at the Friedrich-Miescher-Laboratory of the Max Planck Society. In 1999 he became Professor at the University of California at Berkeley. Since 2001, he is director at the Max Planck Institute of Neurobiology in Martinsried and head of the department ‘Circuits – Computation – Models’.

Alexander Borst is a member of the Bavarian Academy of Sciences, of the German Academy of Sciences Leopoldina and of the European Molecular Biology Organization EMBO. For his work, he received the Otto Hahn Medal of the Max-Planck-Society, the FENS Award from the Federation of European Neuroscience Societies and the Valentino Braitenberg Award in Computational Neurobiology.

How fly neurons compute the direction of visual motion. 

Abstract: Detecting the direction of image motion is important for visual navigation, predator avoidance and prey capture, and thus essential for the survival of all animals that have eyes. However, the direction of motion is not explicitly represented at the level of the photoreceptors: it rather needs to be computed by subsequent neural circuits. The exact nature of this process represents a classic example of neural computation and has been a longstanding question in the field. Our results obtained in the fruit fly Drosophila demonstrate that the local direction of motion is computed in two parallel ON and OFF pathways. Within each pathway, a retinotopic array of four direction-selective T4 (ON) and T5 (OFF) cells represents the four Cartesian components of local motion vectors (leftward, rightward, upward, downward). Since none of the presynaptic neurons is directionally selective, direction selectivity first emerges within T4 and T5 cells. Our present research focuses on the cellular and biophysical mechanisms by which the direction of image motion is computed in these neurons.