(A and D) Coronal sections through E13.5 ErbB4 heterozygous (A) and ErbB4 mutant (D) brains showing nuclear staining and DiI labeling (arrowheads in D) after dorsal thalamic (dTh) injections.
(B and E) Higher magnifications of the images shown in (A) and (E), respectively.
(C and F) Schematic representation of the pathway taken by TCAs in a control situation (C) or in the absence of ErbB4 function (F).
(G) Experimental paradigm used to analyze the effect of a dominant-negative form of ErbB4 (dnErbB4) in the guidance of dTh axons.
(H and I) GFP immunohistochemistry showing TCAs as they extend through the striatum (Str) toward the neocortex (NCx) in control (H) and Gfp + dnErbB4 electroporated slices (I).
(J) Experimental paradigm used to test the growth of E13.5 wild-type or ErbB4−/− dTh explants in wild-type telencephalic slices.
(K and L) DiI labeling and nuclear staining showing wild-type (K) and ErbB4−/− (L) TCAs as they extend through wild-type telencephalic slices. GP, globus pallidus; Hyp, hypothalamus; PCx, piriform cortex. Scale bars = 1 mm (A, D, H, I, K, and L) and 200 μm (B and E).