All data at P14 unless otherwise stated. (A) Immunolabelling for Olig2 and CC1 antigen visualizes differentiated OLs in Gria3null2+/+ and Gria3null2–/– mice. (B) The density of CC1+ OLs is significantly less (by ∼27%) in Gria3null2–/– mice relative to Gria3null2+/+ controls at both P7 and P14 (t- or Mann-Whitney tests with Holm-Bonferroni correction; n = 7, 14, 7 and 6 mice at P7, P14, P21 and P70, respectively, for Gria3null2–/–; n = 5, 14, 9 and 6 mice at P7, P14 and P21 for Gria3null2+/+. >800 cells were counted per mouse at all ages). Right hand side of the graph visualizes the spread of data at P14. (C) ISH for Enpp6 in Gria3null2+/+ and Gria3null2–/– mice. (D) There is a ∼26% reduction in the density of Enpp6 cells in Gria3null2–/–compared to Gria3null2+/+ (p=0.004, Mann-Whitney test). (E) Pdgfra+ OPs in Gria3null2+/+ and Gria3null2–/– mice. (F) There were no significant differences in the density of Pdgfra+ OPs in Gria3null2–/– versus Gria3null2+/+ mice between P3-P70, although there was a trend towards transient reduction in cell density at P14 in Gria3null2–/– (t- or Mann-Whitney tests with Holm-Bonferroni correction; n = 4, 8, 14, 7 and 8 mice at P3, P7, P14, P21 and P70, respectively, for Gria3null2–/–, n = 4, 6, 14, 9 and 7 mice at P3, P7, P14, P21 and P70 for Gria3null2+/+. >800 cells were counted per mouse at all ages). (G) Cleaved Caspase-3+, Olig2+ OL lineage cells in SCWM of P14 Gria3null2–/– mice. Cells in the rectangle (dotted line) are shown on the right at higher magnification. (H) There was a ∼19% increase in the fraction of Olig2+ cells that expressed cleaved Caspase-3 in Gria3null2–/– compared to Gria3null2+/+ littermate controls (p=0.002, Student’s t-test with Welch’s correction; >800 Olig2+ cells were counted in each mouse). Numbers of mice analyzed are indicated in (D) and (H). Scale bars: 50 μm.