Fig. 8. Ectopic pyramidal cells in the marginal zone of Vldlr mutants. (A,B) Calbindin-immunoreactive neurons were almost absent from the marginal zone in wild-type animals (A), but were numerous in Vldlr mutants (B). (C) Immunostaining for Tbr1, a deep layer marker, revealed labeled cells in the marginal zone of Vldlr mutant mice. (D-G) Immunolabeling for SMI32, a pyramidal cell marker, revealed strongest expression in layer V on sagittal sections through adult neocortex of wild-type mice (D). In Vldlr mutants (E), but not in wild-type animals and ApoER2 mutants, a few SMI32-positive cells were observed in the marginal zone (arrowhead; higher magnification in F). Reminiscent of the reeler phenotype, inverted pyramidal cells were occasionally observed (G). Scale bars: 50 µm in A,B,F,G; 100 µm in C,D,E.