TrkB | Rab7 | |||||
---|---|---|---|---|---|---|
Control | UO126 | U/C | Control | UO126 | U/C | |
Mean dynein density (puncta/μm of axon length) (±SEM)a | 0.1 (0.01) | 0.13 (0.01) | 1.30 | 0.14 (0.01) | 0.2 (0.01) | 1.43 |
Excursive motility (% of total puncta) (±SEM)b | 17.8 (2.1) | 10.8 (1.2) | 0.61 | 13.1 (2.4) | 5.3 (1.3) | 0.40 |
Retrograde motility (% of total puncta) (±SEM)c | 10.7 (1.6) | 5.9 (1.5) | 0.55 | 10.2 (2.0) | 3.6 (1.0) | 0.35 |
Number of puncta | 326 | 273 | 489 | 467 | ||
Number of axons | 37 | 18 | 28 | 20 | ||
Colocalization with IC-1B (% puncta) (±SEM)d | 21.7 (5.7) | 5.9 (2.0) | 0.27 | 54.6 (4.8) | 42.4 (3.2) | 0.78 |
Number of 1B puncta | 83 | 532 | 144 | 495 | ||
Number of cargo puncta | 96 | 489 | 170 | 692 | ||
Number of axons | 26 | 96 | 17 | 61 |
Cultured hippocampal neurons were transfected with either TrkB-GFP or Rab7-GFP, or they were cotransfected with 1B-mRFP and TrkB-GFP or Rab7-GFP. Axons in control or UO126-treated dishes were imaged, and the indicated measurements were obtained as described in Materials and Methods. U/C, Ratio of indicated measurement from UO126-treated cells compared to control cells.
↵aAddition of UO126 caused a significant increase in the density (number of puncta per micrometer of axon length) of both TrkB and Rab7 (p < 0.02 and p < 0.002, respectively; Student's t test).
↵bAddition of UO126 significantly reduced the excursive motility of TrkB and Rab7 (p < 0.006 and 0.007, respectively; Student's t test).
↵cThe retrograde motility of Rab7 was significantly decreased in the presence of UO126 (p < 0.005, Student's t test).
↵dAddition of UO126 caused a significant decrease in the colocalization of IC-1B dynein with TrkB and Rab7 (p < 0.02 and p < 0.04, respectively; Student's t test).