Gad1 transcripts in the developing vibrissae. (A, B) Expression at E12.5. (A) Gad1 RNA in the supra-orbital (black arrow at top of panel), lateral nasal/maxillary (white arrow) and postoral (black arrow bottom of panel) rows of vibrissae are indicated. (B) Higher magnification view of lateral nasal/maxillary vibrissal rows. The placode corresponding to the β vibrissa follicle  is indicated. (C-F) Gad1 transcripts in the vibrissae at E13.5 (C, D) and E14.5 (E, F). The initial faint expression in the rhinal (white arrow) and anterior maxillary vibrissae (black arrow) at E13.5 is indicated in panel C. (G, H) Coronal sections through the snout of E12.5 embryos hybridized to the Gad1 probe prior to sectioning. Scale bar: A, C, F 750 μm; E 1.5 mm; B 450 μm; D 400 μm; G 200 μm; H 25 μm.