Figure 4.

The segregation of basal and apical vomeronasal neuron axons in the accessory olfactory bulb is unaffected in robo-1^−/− mice. A–L, Parasagittal AOB sections of adult robo-1^+/− (A, C, E, G, I, K) and robo-1^−/− (B, D, F, H, J, L) mice were stained with Gα_o antibodies (A, B, E, F), BS lectin (C–F, I–L), and Gα_i2 antibodies (G, H, K, L). Projections of Gα_o-expressing basal vomeronasal neurons and Gα_i2-expressing apical vomeronasal neurons are restricted to the posterior and anterior regions of the AOB, respectively, in both robo-1^+/− (A, E, G, K) (n = 3) and robo-1^−/− (B, F, H, L) (n = 6) mice. Dotted lines outline the nerve and glomerular layers of the AOB, and arrowheads indicate the anterior–posterior border as defined by BS lectin staining. Scale bar, 125 μm.