In vivo X-ray diffraction and simultaneous EMG reveal the time course of myofilament lattice dilation and filament stretch

@article{Malingen2020InVX,
  title={In vivo X-ray diffraction and simultaneous EMG reveal the time course of myofilament lattice dilation and filament stretch},
  author={Sage A. Malingen and Anthony M. Asencio and Julie A. Cass and Weikang Ma and Thomas C. Irving and Thomas L. Daniel},
  journal={Journal of Experimental Biology},
  year={2020},
  volume={223}
}
ABSTRACT Muscle function within an organism depends on the feedback between molecular and meter-scale processes. Although the motions of muscle's contractile machinery are well described in isolated preparations, only a handful of experiments have documented the kinematics of the lattice occurring when multi-scale interactions are fully intact. We used time-resolved X-ray diffraction to record the kinematics of the myofilament lattice within a normal operating context: the tethered flight of… 

Figures and Tables from this paper

In vivo x-ray diffraction and simultaneous EMG reveal the time course of myofilament lattice dilation and filament stretch
TLDR
While lattice kinematics were predictable within trials, the model could not create predictions across trials, indicating that the variability the authors see across trials may be explained by latent variables occurring in this naturally functioning system.
Active muscular hydraulics
TLDR
A minimal multiscale model of muscle dynamics is proposed that describes muscle as an active sponge and it is shown how contractions generically induce intracellular fluid flow and power active hydraulic oscillations which dictate the fastest rate of muscle contraction.

References

SHOWING 1-10 OF 65 REFERENCES
In vivo x-ray diffraction and simultaneous EMG reveal the time course of myofilament lattice dilation and filament stretch
TLDR
While lattice kinematics were predictable within trials, the model could not create predictions across trials, indicating that the variability the authors see across trials may be explained by latent variables occurring in this naturally functioning system.
Insight into the actin-myosin motor from x-ray diffraction on muscle.
TLDR
Results of x-ray diffraction experiments revealed structural changes in contracting muscles which are interpreted in terms of molecular movements that underlie force generation, but changes in the layer line intensities observed in response to various perturbations cannot be explained by tilting of the lever arm.
X-ray diffraction evidence for myosin-troponin connections and tropomyosin movement during stretch activation of insect flight muscle
TLDR
The time-resolved sequence of molecular changes suggests a mechanism for stretch activation, in which troponin bridges mechanically tug tropomyosin aside to relieve tropomyOSin’s steric blocking of myosin–actin binding, which enables subsequent force production.
The filament lattice of striated muscle.
TLDR
The effects of lattice change on muscle contraction in vertebrate skeletal and cardiac muscle and in invertebrate striated muscle are reviewed and the force developed, the speed of shortening, and stiffness are compared with structural changes occurring within the lattice.
Elastic Energy Storage and Radial Forces in the Myofilament Lattice Depend on Sarcomere Length
TLDR
A fully three-dimensional spatially explicit model of muscle is developed to isolate the locations of forces and energies that are difficult to separate experimentally, suggesting a mechanism by which muscle function shifts as force production declines, from motor to spring.
...
...