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Abstract We have used kymograph analysis combined with edge detection and an automated computational algorithm to analyze the axonal transport kinetics of neurofilament polymers in cultured neurons at 30 ms temporal resolution. We generated 301 kymographs from 136 movies and analyzed 726 filaments ranging from 0.6 to 42 µm in length, representing ∼37,000 distinct moving and pausing events. We found that the movement is even more intermittent than previously reported and that the filaments undergo frequent, often transient, reversals which suggest that they can engage simultaneously with both anterograde and retrograde motors. Average anterograde and retrograde bout velocities (0.9 and 1.2 µm s−1, respectively) were faster than previously reported, with maximum sustained bout velocities of up to 6.6 and 7.8 µm s−1, respectively. Average run lengths (∼1.1 µm) and run times (∼1.4 s) were in the range reported for molecular motor processivity in vitro, suggesting that the runs could represent the individual processive bouts of the neurofilament motors. Notably, we found no decrease in run velocity, run length or run time with increasing filament length, which suggests that either the drag on the moving filaments is negligible or that longer filaments recruit more motors.
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Decoding the complex journeys of RNAs along neurons
Abstract Neurons are highly polarized, specialized cells that must overcome immense challenges to ensure the health and survival of the organism in which they reside. They can spread over meters and persist for decades yet communicate at sub-millisecond and millimeter scales. Thus, neurons require extreme levels of spatial-temporal control. Neurons employ molecular motors to transport coding and noncoding RNAs to distal synapses. Intracellular trafficking of RNAs enables neurons to locally regulate protein synthesis and synaptic activity. The way in which RNAs get loaded onto molecular motors and transported to their target locations, particularly following synaptic plasticity, is explored below.
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- Award ID(s):
- 2231247
- PAR ID:
- 10583262
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Nucleic Acids Research
- Volume:
- 53
- Issue:
- 7
- ISSN:
- 0305-1048
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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