[1] Heidelberg Univ, Inst Neurobiol, Interdisciplinary Ctr Neurosci IZN, D-69120 Heidelberg, Germany
[2] Heidelberg Univ, Otto Meyerhoff Zentrum, D-69120 Heidelberg, Germany
[3] Univ Belgrade, Fac Med, Inst Biochem, YU-11000 Belgrade, Serbia
[4] Univ Ulm, Electron Microscopy Facil, D-89069 Ulm, Germany
[5] Univ Bergen, Inst Biochem & Mol Biol, N-5009 Bergen, Norway