Figure 6.
Mutant polyQ huntingtin specifically alters retrograde transport of TrkB vesicles in striatal dendrites. A, Representative images (4 different images of the Qdot705 channel): A1–A4, for Hdh+/+. A1′–A4′, for HdhQ111/Q111. Images show the position of Qdots within the microfluidic devices after 2 min incubation of the primary striatal neurons from Hdh+/+ (top) or HdhQ111/Q111 (bottom) mice with biotinylated BDNF. Left, Microchannels in bright field and merge. The other representative images only show the Qdot positions. The Qdots are mostly located in the channels and cell body compartment for wild-type cells, whereas they are mostly in the dendrite compartment in mutant situation. B, Only very few Qdots could be detected in chambers containing dendrites that were not treated with BDNF. C, Quantification of >200 microchannels reveals a significant reduction in the number of TrkB-containing vesicles that crossed the channels to reach the cell bodies of striatal neurons in HD neurons. Error bars indicate SEM. **p < 0.01 (unpaired, one-tailed t test). ***p < 0.001 (unpaired, one-tailed t test).