Figure 3: Morphological analysis of the neuronal and glial components in Cdc42ep4^fl/fl and Cdc42ep4^−/− cerebellar cortices.

(a) Double-label IF of WT and KO cerebellar cortices for a Purkinje cell marker Car8 (red) and a parallel fibre (that is, granule cell) marker VGluT1 (top, green) or a climbing fibre marker VGluT2 (bottom, green). No obvious morphological anomaly, including aberrant CF–PC innervation, was found in the major neuronal components of KO-derived samples. Scale bar, 20 μm. (b) Transmission electron microscopy images of WT and KO molecular layers. No obvious ultrastructural difference was found between the genotypes. PF, parallel fibre terminal or bouton. PC, dendritic spine of Purkinje cell. Bergmann glial processes are tinted. Scale bar, 200 nm. (c) Cumulative histogram of PSD length of the PF–PC synapses, showing no significant difference between the genotypes (n=92 synapses from two littermates for each genotype, NS, P>0.05 by Kolmogorov–Smirnov test). (d) Quantitative immunoblot of WT and KO cerebellar PSD fractions for GluA1, GluA2 and GluA4 (the major subunits of the AMPARs), each normalized with PSD-95. There was no significant quantitative difference by genotype (n=3, NS, P>0.05 by t-test).