Dehaene S, Changeux JP. Reward-dependent learning in neuronal networks for planning and decision making. Progress in Brain Research 2000;126: 217- 29. Borday C, Wrobel L, Fortin G, Champagnat J, Thaeron-Antono C, Thoby-Brisson M. Developmental gene control of brainstem function: views from the embryo. Progress in Biophysics and Molecular Biology 2004;84: 89- 106.