Fig. 3

Wnt5a promotes axonal elongation via a CaMKK-CaMK cascade in immature cortical neurons. a Cortical neurons were stimulated with Wnt5a in the presence or absence of KN-93, a general CaMK inhibitor. Wnt5a treatment facilitated axonal elongation and this effect was potently inhibited in neurons treated with KN-93. Number of neurons: n = 15 for all groups. b Treatment with STO-609, a selective inhibitor of CaMKKα/β, the upstream kinases of CaMKI/IV, severely impaired Wnt5a-dependent facilitation of axonal elongation. Number of neurons: n = 15 for all groups. c Left, Wnt5a-dependent facilitation of axonal outgrowth was abolished in CaMKKα/β-DKO neurons. Note that the basal growth of axons was strongly impaired in CaMKKα/β-DKO neurons, in the absence of Wnt5a. Right, similar to axonal elongation, basal dendritic growth was inhibited in CaMKKα/β-DKO neurons in the absence of Wnt5a. However, dendritic growth was not facilitated by Wnt5a administration, either in the WT or DKO. Number of neurons: n = 15 for all groups. Insets in both graphs show no significant changes in axonal or dendritic growths in the cultured cortical neurons from either WT or CaMKKα/β double heterozygous (DHT) mice. ***p < 0.001, **p < 0.01, *p < 0.05, n.s., not significant (p > 0.05) (two-way ANOVA with Turkey’s test)