Extended Data Figure 3: Additional marker expression for astroglial cells and progenitor cells in the human DG at different ages.

a, Vimentin⁺ and GFAP⁺ cells in the hippocampus from 22 gestational weeks to 35 years. Vimentin is widely expressed during fetal and early postnatal development and is mostly restricted to protoplasmic astrocytes in the molecular layer in adults. GFAP is not expressed at 22 gestational weeks, but at birth a few vimentin⁺GFAP⁺ cells are present in the hilus and GCL (arrowhead). Interestingly, some vimentin⁺GFAP⁻ cells with a radial morphology (arrow) are observed in samples at 1 year of age, but not at the other ages. In adults, GFAP and vimentin are not co-expressed (right, high-magnification of thin GFAP⁺vimentin⁻ fibres within the GCL). b, Vimentin⁺Sox2⁺ simpler elongated cells in the hilus at 1 month (arrow) and protoplasmic astrocytes in the molecular layer at 35 years of age (arrow). c, SOX2⁺ cells are abundant in the GCL and hilus at 22 gestational weeks, and co-express ALDH1L1 in the brain at birth and in older individuals (arrows). d, At birth, there are few ALDH1L1⁺GFAP⁺ cells in the DG, but by 13 years of age many stellate astrocytes express both of these markers. Right, z stack of radial GFAP⁺ processes that are surrounded by ALDH1L1 staining. Scale bars, 100 μm (a (top row)), 10 μm (a (bottom row and insets), b–d) and 2 μm (d (z-stack)).