Figure 4

Cortical thickness and layer proportion analysis in C57Bl/6 and BTBR mice at different developmental stages. Coronal sections of C57Bl/6 and BTBR brains were stained with nuclear markers, and the thickness of the cortical plate, as well as its composite layers, was measured in P7 and adult animals. Qualitative (A, B) and quantitative (C) analysis reveals a significant increase in cortical thickness of V1, but not S1, at P7 (n = 7 animals for each strain, Student’s t-tests). However, the proportion of layers that comprise the cortical plate is not significantly different between strains (n = 7 animals for each strain; thickness of each layer as a percentage of total cortical thickness compared with Student’s t-tests; (D)). By adulthood, there is no significant difference in cortical thickness between the two strains, although there is a general trend towards a thinner cortex in the BTBR mouse (E-G). The proportion of layers comprising the cortical plate is again unchanged in adulthood between the two strains (n = 6 animals for each strain; (H)). ***P < 0.001. Scale bar = 100 μm for (A) and (B) and 200 μm for (E) and (F). BTBR = BTBR T + tf/J, n.s. = not significant.