Fig. 2. MGE cells in the subventricular and marginal zones at two (E15.5) and four (E17.5) days after transplantation. (A) Higher magnification of the boundary between the developing striatum and neocortex at 2 days after transplantation reveals the shape and orientation of tangentially migrating neurons. Most PKH26-labeled MGE neurons migrate close to the neocortical ventricular zone and only few cells are observed in the marginal zone. (B) Double labeling for BrdU reveals most of the tangentially oriented cells in the neocortical SVZ. (C) Tangentially migrating cells do not use corticofugal axons in the upper intermediate zone, which were labeled with antibody against neurofilament-145. (D) Confocal image of differentiating MGE-derived neurons in the marginal zone 4 days after transplantation. (E) Quantification of the density of graft-derived cells demonstrates the shift from the subventricular (SVZ) to marginal zone (MZ) between days 2 and 4. (F) Immunostaining of transplanted MGE cells expressing alkaline phosphatase in one day old pup (7 days after transplantation) reveals that some of the MGE-derived cells (green) express GABA (red). (G) Staining with antibody CR-50 against reelin (red) revealed that MGE-derived cells (green) are found close to clusters of CR-50 positive cells but they are not double-labeled.