Fig. 4.

R1-derived serotonergic system severely changed in absence of En1. (A-R) At E14.5 all serotonergic markers investigated showed a severely changed expression pattern in absence of En1. Pet1 (A-F), Sert (G-L) and Gata3 (M-R) lost expression in DRN in medial section (asterisks). In paramedial sections the cytoarchitecture is changed (arrowheads) (B′,H′,N′,E′,K′,Q′). (S-Z) At P42 Sert expression is strongly diminished (asterisks) and the Sert-expressing neurons that were still present, are differently organized in En1KO brains compared to control (arrowheads). (Para)medial sections as shown in schematic, area shown indicated by a red box in schematic. Scale bars: 100 μm.