(A–E) In situ hybridization of ephrin-A ligands within the VB/POm at P4. Expression of ephrin-A2 and -A3 (B and C) is observed throughout the VB/POm in a uniform fashion. In contrast, the expression of ephrin-A5 is observed in a distinct ventro-lateral gradient within the VB/POm (E). Expression of ephrin-A1 and –A4 was low/not expressed (A and D). (F–J) In situ hybridization of ephrin-A ligands within the cortex. Strong expression of ephrin-A2, -A3, and –A5 (G, H and J) are observed in the cortex, while ephrin-A1 and –A4 expression was low/not expressed. V = Visual Cortex, S = Somatosensory Cortex, Au = Auditory Cortex. Scale bar = 500 μm.