Sema7A and plexinC1 expression in the forebrain. In situ hybridization for Sema7A and plexinC1 on consecutive coronal (A-F, I, J) and sagittal (G, H, K, L) sections of the cortex and striatum. Dorsal is to the top. (A, B) At E19, Sema7A and plexinC1 are expressed in the cortical plate (CP), whereas Sema7A is also expressed in the subplate (SP). In the postnatal (C, D) and adult cortex (E, F), Sema7A and plexinC1 can be found in layers II–VI. Note that Sema7A expression is highest in layers II and III in the adult (E). (G, H) Low magnification overview of Sema7A and plexinC1 expression in the adult brain. Note that cortical Sema7A expression is most pronounced within the barrel area of the presumptive somatosensory cortex (arrows indicate the anterior to posterior limits of the barrel cortex within layer V). In addition, Sema7A is strongly expressed in the subiculum (S), hippocampus (Hip), striatum (Str) and thalamus (Th). (I-L) Sema7A is expressed in a mediolateral gradient within the developing (I) and adult (J) striatum. Interestingly, plexinC1 is expressed in a lateromedial gradient in the embryonic (J) but not adult (L) striatum. 7A, Sema7A; C1, plexinC1; cc, corpus callosum; CX, cortex; GP, globus pallidus; IC, inferior colliculus; SSZ, striatal subventricular zone. Scale bar 140 μm (A, B), 120 μm (C, D), 2.2 mm (E, F), 17 mm (G, H), 180 μm (I, J), and 1.3 mm (K, L).