[1] Univ Cologne, Inst Neurophysiol, D-50931 Cologne, Germany
[2] Univ Cologne, Ctr Mol Med Cologne, D-50931 Cologne, Germany
[3] Univ Cologne, Inst Vegetat Physiol, D-50931 Cologne, Germany
[4] Univ Western Ontario, Canadian Inst Hlth Res Grp Skeletal Dev & Remodel, Dept Physiol & Pharmacol, Fac Med & Dent, London, ON N6A 3K7, Canada
[5] CNRS, UMR 6542, Fac Sci, F-75700 Paris, France
[6] Univ Halle Wittenberg, Julius Bernstein Inst Physiol, Halle, Germany