Figure 5.
Expression of 5-HT3A in the developing embryo at E14.5. (A,E): Brightfield coronal views of the entopeduncular area (AEP, A) and the caudal ganglionic eminence (CGE, E). (C,D,G,H): Coronal sections where arrows point to restricted expression of 5-HT3A mRNA in wild-type mouse (C,G) and GFP immunostaining from a 5-HT3A:GFP transgenic mouse (D,H). The main sites of 5-HT3A expression where located at the telencephalic–diencephalic junction, in AEP (A,B,D) and in CGE (E,F,H). (B–F) Alternate sections of the preparations shown in (A,E) showing Dlx1/2 expression. (I–L) Coronal section taken at the level of the CGE indicated by the asterisk in (H) showing cells double labeled for GFP (green) and the postmitotic marker tuj-1 (red). (J–L) Higher magnifications of the region shown in (I). Arrow points to a double-labeled cell and the open arrowhead points to a cell expressing only tuj-1. (M) Whole-mount preparation of a E14.5 5-HT3A:GFP embryo showing restricted expression of GFP+ cells in the CGE. (N) Coronal section of the caudal cortex (boxed in H) of a 5-HT3A:GFP embryo stained for GABA (red) showing GABA+ cells in the migratory pathway of interneurons (LIZ). (O–Q) High-power view of the section shown in (N). Note that only a proportion of GABA+ cells express GFP (arrows) and that all GFP+ cells in LIZ express GABA. The asterisk points to a GABA-positive cell that is not expressing GFP. LGE, lateral ganglionic eminence, LIZ, Low intermediate zone, MGE, medial ganglionic eminence. Scale bar: (A–C,E–G) 1 mm; (D,H) 800 μm; (I,N) 125 μm; (J–L) 90 μm; (M) 500 μm; (O–Q) 75 μm.