TABLE 4.
Summary of effects of TRAK2 gene knockdown on mitochondrial dynamics in axons of hippocampal pyramidal neurons
Hippocampal neurons were transfected in parallel at 3 DIV with either pDsRed1-Mito, pDsRed1-Mito + pGreenTRAK2scr, pDsRed1-Mito + pGreenTRAK2, or pDsRed1-Mito + pGreenTRAK2-2. At 6 DIV, co-transfected cells were identified, mitochondrial dynamics were imaged by confocal microscopy, and the results were analyzed using Volocity software all as described under “Experimental Procedures.” Oscillating mitochondria are defined as those that are displaced >2 μm from one site. Values are the means ± S.E. from n = 35 images from n = 18 neurons for pDsRed1-Mito (343 mitochondria imaged), n = 29 images from n = 15 neurons for pDsRed1-Mito + pGreenTRAK2scr transfections (251 mitochondria imaged), n = 39 images from n = 23 neurons for pDsRed1-Mito + pGreenTRAK2 (325 mitochondria imaged), and n = 27 images from n = 15 neurons for pDsRed1-Mito + pGreenTRAK2-2 (306 mitochondria imaged) for at least n = 3 independent transfection experiments.
| Clones transfected | Mitochondrial density | Velocity | Fusion events/10 mitochondria | Fission events/10 mitochondria | Oscillating mitochondria | Stationary mitochondria | Mobile mitochondria | Anterograde mitochondria | Retrograde mitochondria |
|---|---|---|---|---|---|---|---|---|---|
| μm−1 | μm/s | % | % | % | % | % | |||
| pDsRed1-Mito | 0.17 ± 0.03 | 0.41 ± 0.1 | 0.8 | 0.8 | 2 ± 1 | 69 ± 5 | 31 ± 5 | 14 ± 3 | 15 ± 3 |
| pDsRed1-Mito pGreenTRAK2scr | 0.14 ± 0.03 | 0.43 ± 0.11 | 0.7 | 0.7 | 1 ± 1 | 65 ± 5 | 35 ± 4 | 17 ± 2 | 17 ± 2 |
| pDsRed1-Mito pGreenTRAK2 | 0.15 ± 0.03 | 0.42 ± 0.07 | 0.7 | 0.7 | 1 ± 1 | 67 ± 3 | 33 ± 3 | 16 ± 1 | 16 ± 2 |
| pDsRed1-Mito pGreenTRAK2-2 | 0.18 ± 0.03 | 0.34 ± 0.05 | 0.6 | 0.8 | 1 ± 1 | 68 ± 3 | 32 ± 3 | 16 ± 2 | 15 ± 2 |