Both telencephalon and non-telencephalon astrocytes were further split into subtypes expressing Gfap at high or low levels (Figure 3G). This distinction likely corresponds to the fibrous astrocytes of the white matter and the glia limitans underneath the pia (Gfap-high) versus the protoplasmic astrocytes of the parenchyma (Gfap-low). The difference between subtypes in both cases involved a similar set of genes, suggesting that this represents an independent axis of variation that can be activated in both telencephalon and non-telencephalon astrocytes as a function of local environmental cues, particularly the distance from the pia and white matter.
