Figure 1

Postnatal hippocampal-derived neurospheres are composed of subpopulations of progenitor and immature cell types. Schematic of spontaneous specification over the course of neurosphere expansion in vitro. Pertinent lineage markers are indicated (a). Representative digital micrographs depicting antigenic lineage analysis of NPC populations through the central sections of serial cryosections of neurospheres cultured in the absence of laminin are depicted in b-h. Scale bars, 50 μm, insets 25 μm. Type 1 NPCs expressing GFAP and nestin localized to the periphery of spheres (b, arrows and inset); Type 2a NPCs expressing nestin were found toward the centre of the core (b, arrowhead). Type 3 neuroblasts (c, d, arrows and inset) and immature neurons (d, e, arrows and inset) were found in clusters throughout serial sections. NG2⁺ (f, arrows and inset) and PDGFαR⁺ (g, arrows and inset) OPCs and RIP⁺ oligodendrocytes (h, arrows and inset) tended to be found along the neurosphere periphery. Culture on a laminin matrix increased the percentage of NPCs that retained a nestin⁺ NPC identity and decreased the percentage of cells that specified to neuroblasts, immature neurons, and OPCs (i). Data represent mean of 5–15 sections counted over n = 5–10 cultures/condition ± standard error of measurement (SEM). *p < 0.05, **p < 0.01, ANOVA, post-hoc Tukey test.