A–F, GFP (green, A–F), NK1R (red, A, B, D, E), ChAT (blue, A, B, D, E), and SST (red, C, F) expression in the ventrolateral medulla of Lbx1GFP/+ and Lbx1GFP/GFP mice at E18. PreBötC neurons (NK1R+/ChAT− and SST+) are present in both Lbx1GFP/+ and Lbx1GFP/GFP mice. B, E, Details of preBötC neurons from A and D, respectively. There is a marked reduction in GFP+ neurons within the network of the ventrolateral medulla (asterisks). Scale bars: A, C, D, F, 200 μm; B, E, 100 μm.