(A) Representative DIC image (24 DIV) with superimposed CTx/ATx perfusion spot (red) and syt-lum and vglut1 staining from the same neuron. (B) Linearized dendrite indicated by the arrow shown in (A) with corresponding syt-lum and vglut1 staining registered to the perfusion area (red). Scale bar = 30 μm and 10 μm in (A) and (B), respectively. (C–D) Analysis of group data. On the abscissa, positive and negative values indicate, respectively, segments distal and proximal from the treated area. (C) Mean (± SEM) normalized vglut1 density in treated and untreated dendritic segments; local perfusion did not affect synaptic density. (D) Mean (± SEM) proportion of vglut1-positive synapses with corresponding syt-lum signal in treated and untreated dendritic segments. Coincident AMPAR blockade (20 μM CNQX, 2 hrs) significantly (* p < 0.05) increased syt uptake in the treated area in neurons locally treated with vehicle relative to those locally treated with TTX or CTx/ATx. For the groups indicated from top to bottom in (D), n = 10 dendrites from 7 cells; 12 dendrites from 8 cells; 14 dendrites from 10 cells; 11 dendrites from 7 cells (21–35 DIV).