Fig 2: Expression of pre- and postsynaptic proteins in KIF3B knockdown cortical neurons. (A,D) Representative confocal images of cortical neurons 72 h after transfection with shScrambled and shKIF3B. (B,C,E,F) The bar graph depicts the corrected total cell fluorescence (CTCF) of Synaptophysin, Piccolo, PSD-95, and VGLUT1 analyzed using ImageJ (NIH). Student t-test, *P < 0.05. Scale bar, 2 µm, N (number of neurons) is indicated per group. Error bars are SEM. Data used for preparing plots are shown in Supplementary Table 4.

Fig 3: KIF3B knockdown increases overall spine density and morphology in cultured cortical neurons. (A) Experimental Schema. (B) Representative confocal images of DIV 17 neurons transfected with shScrambled and shKIF3B for 72 h. (C,D) Quantification of total spine density and morphology of spines. The analysis was carried out with custom MATLAB software. (C) Student t-test, ****P < 0.0001. (D) Student t-test, *P < 0.05, ****P < 0.0001. Scale bar, 20 µm, and 2 µm. N (number of neurons) is indicated per group. Error bars are SEM. Data used for preparing plots are shown in Supplementary Table 2.

Fig 4: KIF3B overexpression reduces dendritic arborization. (A) Experimental schema. (B) Representative confocal images of cortical neurons transfected with eGFP and FLKIF3B. (C) Line graphs depicting the quantification of dendritic arborization (ImageJ, NIH). Two-way ANOVA, **P < 0.01 with Sidak post hoc test, *P < 0.05, **P < 0.01. Scale bar, 20 µm. N (number of neurons) is indicated per group. Error bars are SEM. Data used for preparing plots are shown in Supplementary Table 6.

Fig 5: KIF3B overexpression reduces spine density and morphology in cultured cortical neurons. (A) Experimental Schema. (B) Representative confocal images of DIV 14 neurons transfected with eGFP and FLKIF3B for 48 h. (C,D) Quantification of total spine density and morphology of spines. The analysis was carried out with custom MATLAB software. (C) Student t-test, **P < 0.01. (D) Student t-test, *P < 0.05. Scale bar, 25 µm, and 5 µm. N (number of neurons) is indicated per group. Error bars are SEM. Data used for preparing plots are shown in Supplementary Table 5.