RGMa-mediated repulsion of newborn interneurons is suppressed by Netrin-1.

<p>(A) The extent of interneuron migration was calculated as the ratio of the distal to proximal area (guidance ratio) occupied by migrating cells. (B–E) Anti-βIII-tubulin immunolabeling (red) revealed the extent of interneuron migration out of E14.5 MGE VZ explants placed adjacent to agarose blocks containing control HEK293 cells (B), cells producing Netrin-1 (C), RGMa (D) or RGMa + Netrin-1 (E). Note the significant increase in neuron density on the distal side of the explant in the presence of RGMa (D). (E) Quantification of the guidance ratio for newborn interneuron migration out of the MGE explants in response to guidance cues. Dotted lines indicate the body of the explant. Control, n = 10; Netrin-1, n = 8; RGMa, n = 12; RGMa + Netrin-1, n = 7. *p<0.5, **p<0.01.