Figure 6.

Introduction of wild-type CRMP1 (CRMP1-WT), but not CRMP1-T509A/S522A, into crmp1^−/− neurons rescues the defect in Sema3A responsiveness. A, The cultured cortical neurons of crmp1^−/− mice at E18.5, transfected with CRMP1-WT (a, b, e, f) or CRMP1-T509A/S522A (c, d, g, h) at 11 d in vitro, were applied with (b, d, f, h) or without (a, c, e, g) Sema3A (3 nm) for 24 h, fixed, and then stained with anti-synapsin I (a–d) or anti-PSD-95 (e–h) antibodies. Arrowheads represent typical immunoreactive clusters at EGFP-positive protrusions. Scale bars: 5 μm. B, Quantitative analysis of the effects of Sema3A on the density of synapsin I (a) or PSD-95 (c) clusters, and the area of synapsin I (b) or PSD-95 (d) clusters in crmp1^−/− cultured cortical neurons transfected with CRMP1-WT or CRMP1-T509A/S522A. Each value represents mean ± SEM from 60 neurons of three independent cultures. *p < 0.01 compared with vehicle control.