R H Tolba1, B M Riederer2, R Weiskirchen3. 1. Institute of Laboratory Animal Science and Experimental Surgery, RWTH Aachen University, Aachen, Germany. 2. Department of Fundamental Neurosciences (DNF), University of Lausanne, Lausanne, and Centre for Psychiatric Neuroscience, University Hospital of the Canton de Vaud, Lausanne, Switzerland. 3. Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry, RWTH University Hospital Aachen, Aachen, Germany rtolba@ukaachen.de.