Aim of this project is to develop a technical device that helps blind or visually impaired persons to avoid colliding with other objects. This device will be based on a natural sensor that has been used for millions of years by grasshoppers: a simple neuronal circuit can faithfully warn locusts of impending collision, and, depending on their current behavioural context, the animals avoid colliding into other objects by either hiding, or fleeing, or by letting themselves drop for a short distance during flight. Together with Claire Rind of Newcastle University, who made the discovery that only four single neurons, the LGMDs, are acting as key players in this neuronal circuit, we are now studying this circuit using modern neuroanatomical and neurophysiological techniques. At the same time, work is in progress to assess the needs of blind or visually impaired persons. We’ll thus find which sort of device will help these persons- where it can be worn, in which way it will warn the persons etc. Stefan Wernitznig is studying the neurons involved for his doctoral thesis. The neuroanatomical techniques we are using are based on serial block face SEM (SBEM), an exciting and novel technique that allows us to trace neurons and all their processes, and to map their synaptic connections in 3D. For this, a tissue block is made containing brain tissue of a locust. In the lab of Peter Pölt and Armin Zankel of the Institute of the Institute for Electron Microscopy and Fine Structure Research nearby, a scanning electron microscope is used to visualize the neurons by scanning the block surface. A special diamond knife then repeatedly cuts sections off the block surface, and after each section is removed the block surface is scanned. This leads to serial micrographs from which the neurons can readily be reconstructed.
2012 - 2016