Figure 6. NM neurons for which TrkB expression has been maintained from E8 to E17 have dendrites. A, Embryos were electroporated with Tol2-Dox plasmids and treated with Dox from E8–E17. B, C, Images of rostral and caudal regions of NM respectively, at E17. D, TrkB-coding sequences inserted into pT2K-BI-TRE-EGFP. E, G, NM neurons at E17 from two different embryos in which TrkB expression was maintained from E8–E17. F, H, TrkB immunoreactivity in neurons represented in E and G, respectively. I, TrkB immunostaining of NL ventral dendrites at E12. Area within small dashed lines is the dorsal neuropil, the area within the large dashed lines contains the ventral dendrites (Fig. 1A, refer to schematic). At E12, endogenous TrkB is present more abundantly in the ventral dendrites than in the dorsal dendrites and the level of expression is similar to TrkB resulting from Dox-regulated transgene expression in NM, as illustrated in F and H. Scale bars: (in B, G, E, I) B, C, E–I, 10 μm.