Figure 8.
Regulation of habenular gene expression by Nurr1. A–D, Brn3a and LacZ expression in the habenula of E16.5 Nr4a2+/+ and Nr4a2−/− embryos bearing a Pou4f1tLacZ reporter allele. Neurons and axons do not display the medial displacement observed in Pou4f1−/− embryos, and Brn3a expression is not affected by the loss of Nurr1. E, F, Innervation of the IPN in P0 Nr4a2+/+ and Nr4a2−/− mice carrying a Pou4f1tLacZ reporter allele. Nurr1 expression also identifies dopaminergic neurons in the VTA adjacent to the IPN. G, Changes in gene expression in Nr4a2−/− embryos at E16.5. Nurr1 mediates a subset of the gene expression changes observed in the habenula of Brn3a null embryos. Complete gene names appear in Table 2. fr, Fasciculus retroflexus; hip, hippocampus; R, red nucleus; rs, rubrospinal tract; vtgx, ventral tegmental decussation. Scale bars: A–D, 50 μm; E, F, 100 μm; G, 100 μm.