Prof. Dr. Rüdiger Wehner

 

Main Goals, Keywords

Neurobiology of invertebrates, especially neurophysiology and behavioural analysis of insect vision.

Group Members

1 professor, 1 Ph.D. student, 2 M.Sc. students

Previous and Current Research

The most highly advanced social insects such as bees and ants accomplish amazingly sophisticated navigational tasks. This is a prime example of complex visual behaviour found in animals with limited cognitive capacities. In the Saharan desert ant Cataglyphis we study the visual mechanisms underlying skylight (polarized light) navigation, path integration and piloting by visual landmarks. In using polarized skylight as a compass the insects studied (ants, bees, crickets) have evolved a specialized neural module consisting of polarization-sensitive photoreceptors and interneurons. Other visual modules detect colour gradients in the sky, landmark panoramas along the skyline and self-induced image motion of the ground about which the animals move. The latter information is employed by the insect for gauging distances travelled. We use the combined results of our neurophysiological and behavioural approaches also to design computer models and robotics implementations of the animal’s behaviour.

 

Future Projects

Our research focuses on visually guided behavior in insects, especially desert ants, by combining experimental behavioral analyses with neuroanatomical and neurophysiological approaches. At present, we study (1) the neural pathway involved in deriving compass information from the pattern of polarized light in the sky, (2) the strategies by which landmark information is acquired ontogenetically (while the animals are starting their foraging lives), and (3) how the synaptic organization and hence the neural circuitries in particular parts of the ant’s brain change during the ant’s lifetime, and how these changes are correlated with the various behavioral tasks to be accomplished at different times of the life cycle. The latter project includes immunocytochemical staining, confocal microscopy, image processing, electron microscopy, and 3D reconstructions.

Techniques and Equipment

Intracellular electrophysiological recordings and stainings, neuroanatomy, immunohistochemistry, computer and hardware simulations, robotics implementations, optical stimulation devices, mechanical and electronic equipment for recording spatial orientation patterns, digitizing the records, manipulating the visual surround of freely walking animals.

Selected Publications

• Müller, M., Wehner, R. Path integration provides a scaffold for landmark learning in desert ants. Curr. Biol. 20, doi:10.1016/j.cub.2010.06.035 (2010). (Print version will appear on 4 Aug 2010).
• Stieb, S.M., Münz, T.S., Wehner, R., Rössler, W. Visual experience and age affect synaptic organization in the mushroom bodies of the desert ant Cataglyphis fortis. Develop. Neurobiol. 70: 408-423 (2010).
• Seid, M.A., Wehner, R. Delayed axonal pruning in the ant brain: a study of developmental trajectories. Develop. Neurobiol. 69: 350-364 (2009).

Funding

German Science Foundation, Promotor Foundation

URL

http://www.zool.uzh.ch/Research/Neurobiology/Wehner.html