Knockdown of SNARE proteins in cultured RGCs. (A) Immunoblots showing each SNARE protein in the control (Ctrl) RGCs and RGCs with each SNARE protein depleted. (B and C) Cell aggregation assay of control RGCs and RGCs with each SNARE protein depleted and treated with or without 5 mM EGTA. The density of the aggregates was determined based on three independent experiments (C). Scale bar, 100 µm. (D) N-cadherin (Ncad; green) and VAMP3 (upper, red), VAMP4 (middle, red), or VAMP5 (lower, red) stained with DAPI (blue) in the control and VAMP3-, VAMP4-, or VAMP5-depleted RGCs. Scale bar, 10 µm. The bar graph represents the means ± SEM. Significance was calculated using two-tailed paired Student’s t tests. Statistical significance is indicated by *P < 0.05 or **P < 0.01.