Co-registration of gene expression and INCs at the S-V boundary in P10 control and enucleated mice. High magnification views of 100 μm coronal hemisections following in situ RNA hybridization with a probe directed against ephrin A5 in P10 (A1-C1) control and (A2-C2) enucleated mice. Tracing of INCs after placement of DiA or DiI in putative visual and somatosensory cortex in P10 (D1-F1) control brains and (D2-F2) brains from enucleated mice. Sections in A1-A2, B1-B2, C1-C2 were matched with D1-D2, E1-E2, F1-F2 sections using anatomical landmarks. In control brains, ephrin A5 expression is excluded from medial regions of the parietal cortex (arrows in A1-C1). This region does not possess any retrogradely labeled cells from dye placement in the somatosensory cortex (absence of green labeling at arrow in D1, E1, F1) but does contain retrogradely labeled cells and axons from a visual DPL (red labeling at and below arrow in D1, E1, F1). Following enucleation, both ephrin A5 expression (A2-C2) and cells projecting to the somatosensory cortex (green labeling at arrow in D2-F2) were observed medially in the parietal cortex, indicating that gene expression and INCs are co-registered. Dorsal (D) is up and lateral (L) is to the right. Asterisks indicate the medial limit of ephrin A5 expression (A1-C1, A2-C2) or labeling from a somatosensory DPL (D1-F1, D2-F2). Scale bars = 1,000 μm. DiA: 4-(4-(dihexadecylamino)styryl)-N-methylpyridinium iodide; DiI: 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate; DPL: dye placement location; INC: ipsilateral intraneocortical connection; P: postnatal day; S-V: somatosensory-visual.