Figure 5

Defective Glut3 trafficking in the brain of adult HD ^140Q/140Q mice. A) Antibody binding to detect cell surface Glut3 and GABAα1 in non-permeabilized brain sections of 9–10 month old WT and HD mice. To ascertain that anti-Glut3 and anti-GABAα1 antibodies labeled only cell surface molecules, we omitted detergents in all buffer solutions used for this assay to preserve the intactness of the plasma membrane. Antibodies bound to cell surface Glut3 and GABAα1 were detected using the immunoperoxidase method. Shown in A are images of Glut3 labeling obtained with a SPOT camera. Three WT and 3 age- and gender- matched HD mice were used for analysis. B) and C) Bar graphs show results of densitometry of Glut3 labeled neurons in brain slices for Glut3 surface expression and neuronal cross-sectional area in the cortex and the striatum of adult WT and HD mice. The data were obtained from digital images of 12 microscopic fields of 6 WT and 6 HD brain sections from 2 WT and 2 HD mice, which were treated under exactly the same conditions. The arbitrary units (A.U.) measured with NIH ImageJ were used for calculating Mean ± SD signal intensity per cell. Statistical significance was determined by two-tailed Student’s t-test using N = 12 microscopic fields. D) Antibody binding to detect cell surface GABAα1 in non-permeabilized brain sections. Brain sections were from the same mice as used for detecting Glut3 expression in A). Shown are images obtained with a SPOT camera. E) and F) Bar graphs show results for cross sectional areas and signal intensities of GABAα1 positive neurons in the cortex A. Digital images were taken from 7 microscopic fields from 4 WT and 4 HD brain sections from 2 WT and 2 HD mice in (E) and for GABAα1 signal intensities in (F). Two sections of each animal were used for analysis. For each section, one or two microscopic fields were selected. Error bars in both E and F represent standard deviations. Two-tailed Student’s t-test was performed to determine the statistical significance using N = 7 microscopic fields.