In CN, we observed that M13C was significantly enriched with markers of astrocytes from previous studies (P = 1.9 × 10−24, P = 6.6 × 10−8 and P = 1.0 × 10−7 from refs. 30,31,33, respectively; Supplementary Table 7). These observations were interesting to us, as another, much larger, module with characteristics of astrocytes (M15) had already been identified in every network, including CN (Figs. 2 and 5, Table 1, and Supplementary Table 2). Although M13C was highly enriched with markers of astrocytes, several genes that are typically expressed in neuroblasts or immature neurons also showed strong membership for this module, including CD24 (ref. 42) and DPYSL3 (ref. 43) (Supplementary Table 5). Also identified in this module was the transcription factor ASCL1 (Supplementary Table 5), which is involved in committing multipotent progenitors to a neuronal fate44. These observations suggested that M13C has characteristics that are mixed between astrocytes and immature neurons. Such characteristics are thought to exist amongst a heterogeneous population of cells with neurogenic properties in the adult SVZ39,40. Because samples from CN were taken from the head of
