Subregion-specific expression of RGMs and Neogenin in the hippocampus.

<p><i>In situ</i> hybridization (A–C, J–L) and immunohistochemistry (D–I, M–O) on coronal mouse brain sections at E16.5 (A–I) and P5 (J–O). Sections in D–I and M–O are counterstained in blue with fluorescent Nissl. (A–F) RGMa mRNA and protein are expressed in the ventricular zone (VZ), dentate gyrus (DG) and cornu ammonis (CA) region. Strong expression of RGMb mRNA and protein is detected in the pial surface lining the hippocampal fissure (HF). Neogenin transcripts and protein are widely expressed in the developing hippocampus (Hip). (G–I) Immunostaining with isotype matched controls. (J–L) <i>In situ</i> hybridization at P5 shows strong but differential expression patterns of <i>RGMa</i>, <i>RGMb</i> and <i>Neogenin</i> in the CA pyramidal cell layers (Pyr). In addition, strong expression of <i>Neogenin</i> is detected in the granular layer (GC) of the DG. (M–O) Immunohistochemistry reveals expression of RGMa and weak expression of RGMb in the stratum lacunosum moleculare (SLM) and fimbria (FIM). Neogenin strongly labels different hippocampal layers. CX, cortex; Hb, habenula; HC, hippocampal commissure; PO, polymorph layer; SO, stratum oriens; SR, stratum radiatum; Th, thalamus. Scale bar A–C: 400 µm, D–F: 300 µm, G–I: 300 µm, J–L: 500 µm and M–O: 400 µm.