Fig. 3. Forebrain-derived neurospheres use normal migratory routes and give rise to neurons with the characteristics of olfactory bulb granule cells and cortical interneurons when transplanted to the forebrain. Constitutive EGFP-expressing forebrain-derived neurospheres were transplanted into the neonatal forebrain (P4) and analyzed at P21. Neurosphere-derived cells were using normal migratory routes and were found in various regions of the brain (A). GABA-immunopositive cells with the morphology of granule neurons were found in the granule cell layer of the olfactory bulb (B), and neuroblasts utilizing chain-migration were observed within the olfactory stream and expressed Tuj1 (C). GABA-positive cells were found distributed over most layers of the cortex (D). Some cells stayed close to the graft site and were expressing GFAP (E). Scale bars: 1 mm in A; 50 µm in B1,C1,D1,E1; 20 µm in B2,C2,D2,E2. Note that regions shown in boxes B1-E2 represent higher power taken from the approximate regions shown in A and that the two higher power pictures in C1 versus C2, as well as D1 versus D2, are different examples.