Program in Neuroscience, University of Fribourg, Switzerland
Dr. Guenter Rager
Institute of Anatomy and Special Embryology
University of Fribourg
1700 FRIBOURG
SWITZERLAND
phone +41-26-300 9540
email Guenter.Rager@unifr.ch
Website
Development of the neural network
The main aim of our research group is to understand the developmental processes and mechanisms responsible for producing the adult neural network. In particular, we are investigating the formation of topologically organized projections, and the separation and segregation of groups of neurones into compartments and cell assemblies. We are focusing our attention on the development of the retina, the optic pathway, the interaction of retinal fibres with their target and the development of the target itself. As animal models, we are using chick embryos, developing tree shrews (Tupaia) and particular strains of mice. We began by employing electron-microscopical and electrophysiological techniques, and then moved on to the use of tracers (e.g., autoradiography, HRP and fluorescent dyes), three-dimensional reconstruction and morphometry. More recently, we initiated an investigation of the role of cell-adhesion molecules, such as axonin-1 and NgCAM, in the formation of the retinotectal connection. The results of our studies, thus far, have revealed the topological organization of the visual system to be governed not by a single mechanism, such as chemoaffinity, but by many different interacting processes and factors.
Using the high-resolution, field-emission scanning microscope, we have been able to visualize axonin-1 molecules on the plasma membranes of ganglion and amacrine cells. And we now wish to explore how these molecules contribute to the formation of the retinal microcircuitry. We are also employing molecular biological techniques to address the role of synaptic proteins in establishing connections within the developing visual system. In the target regions (optic tectum, LGN and visual cortex), we are particularly interested in the development of laminae, and also wish to understand the roles played by afferent fibres and extracellular matrix molecules.
In parallel with this basic research, we are also exploring the brain-mind problem and the philosophy of consciousness and self.
Selected publications
Rager G. The development of the retinotectal projection in the chicken. Adv. Anat. Embryol. Cell Biol. Berlin: Springer, 1980
Rager G., Morino P., Schnitzer J. & Sonderegger P. Expression of the axonal cell adhesion molecules axonin-1 and Ng-CAM during the development of the chick retinotectal system. J.Comp.Neurol. 365: 594-609, 1996
Rager G. Das Bewusstsein und seine neurobiologische Erklärung. Theologie und Philosophie 74: 184-204, 1999