Figure 9.

Decreased number of synapses in the mature Kal7^KO neurons in culture. Cortical cultures were prepared from P1 littermate wild-type and Kal7^KO mice. Replicate cultures were fixed at DIV7 (supplemental Fig. S5A, available at www.jneurosci.org as supplemental material), DIV14 (supplemental Fig. S5B, available at www.jneurosci.org as supplemental material), DIV21 (images not shown), and DIV28 (A–F). One set of cultures was visualized with antibodies specific to Vglut1, MAP2, and Kal7 (A–C); the other set was visualized with antibodies to Vglut1, MAP2, and PSD-95 (D–F). Clusters of Vglut1, Kal7, and PSD-95 staining were quantified by observers blinded to genotype. Differences in number of Vglut1-only clusters (excitatory presynaptic terminals; green stars) or number of excitatory synapses (Vglut1–PSD-95 clusters; red circles) between wild-type and Kal7^KO mice were only detected at DIV28 (G, H) (n = 9–12 for Wt; n = 10–12 for KO). Scale bar, 5 μm. Error bars indicate SEM; **p < 0.01.