Figure 3. Patterns of Notch2 (D,E) and nestin (F,G) immunostaining in human dental tissues in different culture conditions. (A) Schematic representation showing ink diffusion (blue) from the cavity area to the dental pulp (asterisk) in a human tooth. (B) The human tooth-slice culture system. The dark blue spot shows the area where the ink-containing tube is placed, thus permitting diffusion of the ink to the dental pulp (asterisk) (Melin et al., 2000). Growth factors can be used instead of the ink to influence pulp cell activities (i.e., migration, proliferation, differentiation). (C) Diffusion of the ink (blue) through the dentin to the dental pulp (asterisk) (Melin et al., 2000). (D) In a cultured human tooth slice, Notch2 immunostaining is localized in odontoblasts and sub-odontoblastic cells (Mitsiadis et al., 2003). (E) Under the influence of TGFß-1, Notch2 immunostaining is localized only in sub-odontoblastic cells (Mitsiadis et al., 2003). (F) Nestin immunostaining is localized around BMP4-releasing beads in cultured pulp explants (About et al., 2002). (G) Nestin immunostaining is detected in pulp cells cultured in the presence of ß-glycerophosphate (About et al., 2000). Abbreviations: b, bead; cav, cavity; d, dentin; e, enamel; n, mineralized nodule; nf, nerve fibers; o, odontoblasts; p, pulp; pc, pulp chamber; pe, pulp explant; soc, sub-odontoblastic cells. Scale bars: 50 µm. Figs. 3F and 3G are reprinted from Am J Pathol 157:287–295, 2000, with permission from the American Society for Investigative Pathology. Figs. 3B and 3C are reprinted from J Dent Res 79:1689–1696, 2000, with permission from the International Association for Dental Research. Figs. 3D and 3E are reprinted from Exp Cell Res 228:101–109 (Mitsiadis et al., "Notch 2 protein...", 2003), with permission from Elsevier.