Fig. 2. In vitro transplantation of ESGPs in hippocampal slice cultures. (A) Slice culture one day after deposition of 20,000 GFP-labeled ESGPs onto the entorhinal cortex. (B) 18 days after implantation, the donor cells have migrated along the pyramidal cell layer and the Schaffer collaterals into the hilar region and the dentate granule cell layer (dashed line) where they developed complex 3D morphologies (inset, digital reconstruction of a grafted GFP-expressing cell composed of 32 individual planes). (C) At this same stage, cross sections through the entire slice preparation revealed donor cells incorporated at various depths in the host tissue. Double labeling with an antibody to GFAP (red). (D) Although some grafted cells retained an immature morphology and expressed NG2 (red), the majority exhibited differentiated glial phenotypes. (E) About 30% of the ESGPs were immunolabeled for nestin, including cells with astrocytic morphology. (F) In addition to GFAP, donor-derived astrocytes expressed S100ß. (G) An ES cell-derived oligodendrocyte (in the EC region) identified using an antibody to CNP. (H) A GFP+ oligodendrocyte that expressed MBP (red) and had tubular processes that indicate myelin formation (stratum oriens, CA1). Scale bars: in A,B, 1 mm; in C, 100 µm; in D-H, 25 µm.