(A) Number of identified protein groups in the different culture types. (B) Established glia markers are de-enriched in neuron-enriched cultures. Bar diagram shows log2 fold change between neuron-enriched cultures and mixed cultures and error bars indicate SEM. (C) Established neuron markers are de-enriched in glia-enriched cultures. Bar diagram shows log2 fold change between glia-enriched cultures and mixed cultures and error bars indicate SEM. (D) Number of quantified astrocyte, oligodendrocyte and microglia marker proteins in glia-enriched versus mixed cultures. (E) Comparison of relative protein expression levels of astrocyte, oligodendrocyte and microglia markers in glia-enriched cultures versus mixed cultures. Error bars show the standard deviation. (F) GO over-representation analysis for 725 ‘neuron-related’ protein groups (detected in ≥2 biological replicates in neuron-enriched cultures and never detected in glia-enriched cultures). (G) GO over-representation analysis for 1,355 ‘glia-related’ protein groups (detected in ≥2 biological replicates in glia-enriched cultures and never detected in neuron-enriched cultures). (H) Different culture types form distinct clusters in a principle component analysis (PCA). For PCA, log2 transformed relative abundances of 3214 protein groups, which were detected in all biological replicates of all culture types, were used.