Effect of GGT-siRNA on BDNF-induced Purkinje cell dendrite development. A) Rat cerebellar slices at DIV2 were pre-treated with GGTi-2147 (2.5 μM) or vehicle (DMSO) for 45 min, followed by the treatment with BDNF (50 ng/ml) for 2 hr. Membrane fractions were separated and subjected to IB with antibodies against Rac and pan-cadherin. Total Rac or GAPDH was probed as loading controls. B) Quantification for the levels of membrane Rac, Rac (m). Data were shown as means ± SEM from three independent experiments. *P < 0.05. Student's t test. C) Representative images of Purkinje cells after transfection with pSUPER or pSUPER-GGTβ-siRNA, without or with 50 ng/ml BDNF treatments. D) Quantification for total dendritic length between neighboring circles. E) Quantification for total dendritic length between the circle of 50 and 75 μm. F) Quantification for the number of crossings at indicated distances from soma. G) Number of crossings at the circle with radius of 75 μm was quantitatively analyzed. Data are shown as means ± SEM (n = 33 for control; n = 44 for GGT-siRNA; n = 23 for BDNF; n = 21 for BDNF with GGT-siRNA). N.S. P > 0.05; *P < 0.05; **P < 0.01; ***P < 0.001. Student's t test. Scale bar = 20 μm.