Fig. 5. EGFP+ astrocytes in ventral but not dorsal cortex of P14 NG2CreBAC:Z/EG tg mice. Coronal sections (50 µm) through dorsal and ventral cortex and corpus callosum from P14 double tg mice were double or triple labeled with rabbit anti-EGFP (green in A,C,D,F,G,J,K,N,O,Q), mouse anti-GFAP (red in B,C,P,Q), mouse anti-S100β (red in E,F; blue in I,J,M,N), and guinea pig anti-NG2 (red in H,J,L,N) antibodies. (A-F) High magnification of EGFP+ astrocytes in ventral cortex. EGFP+ cells that have the typical morphology of protoplasmic astrocytes with bushy processes are immunoreactive for GFAP (A-C) or S100β (D-F). (G-J) EGFP+ cells in dorsal cortex are immunoreactive for NG2. S100β+ protoplasmic astrocytes in dorsal cortex are negative for NG2 and EGFP. (K-N) EGFP+ cells in ventral cortex extending bushy processes characteristic of protoplasmic astrocytes are also immunoreactive for S100β (thin arrows in M and N). EGFP+ NG2 cells are positive for NG2 but devoid of S100β (thick arrows). Some S100β+NG2- cells do not express EGFP (arrowheads). (O-Q) None of the EGFP+ cells in the corpus callosum express GFAP. Yellow areas represent overlap of GFAP and APC from adjacent cells, but the two antigens are never present in the same cells. Scale bars: 20 µm.