The effects of viscosity on the undulatory swimming dynamics of <i>C. elegans</i>

Backholm, Matilda; Kasper, A.; Schulman, Rafael D.; Ryu, William S.; Dalnoki-Veress, Kari

doi:10.1063/1.4931795

Cited by 25 publications

(21 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mutants exhibited a higher frequency than wild-type nematodes. Similar observations on swimming kinematics were reported by other studies [Sznitman et al, 2010a, Backholm et al, 2015. Kinematics have also been studied in An important advantage in studying swimming is that frictional forces and the mechanical power expended by a microswimmer against those forces can be calculated using hydrodynamic models.…”

Section: Introductionsupporting

confidence: 64%

Experimental investigation using micro-PIV of the effect of microRNA-1 deficiency on motility inCaenorhabditis elegans

Ravikumar

Fedrizzi

Prabhakar

et al. 2020

Preprint

View full text Add to dashboard Cite

Caenorhabditis elegans is a microscopic nematode used extensively as a model organism in studies of neuromuscular function and neurodegenerative disorders. A mutation in mir-1 affects signalling at the neuromuscular junction. We investigate the effect of this mutation on the propulsive power exerted by nematodes as they grow in size with age. We compare the motility of wild-type and mir-1(gk276) mutant nematodes in a Newtonian fluid using a two-component, two dimensional (2C-2D) Digital Microscopic Particle Image Velocimetry (µ-PIV) technique. Beating amplitudes of the head and tail, the wavelength of undulatory waves and the swimming speed scale linearly with size in both the wild-type and mutant strains. The beating frequency is independent of size or position along the body. Differences in the magnitudes of these kinematic parameters between the two strains, however, grow systematically with age. The swimming speed scales linearly with the wave speed of the neuromuscular undulation in both nematode strains with a conserved ratio. The magnitude of mean power and mean local fluid circulation in the mutant is significantly lower compared to those of the wild-type animals of the same age. This indicates that a mutation in mir-1 adversely affects motility in C. elegans.

show abstract

Section: Introductionsupporting

confidence: 64%

Experimental investigation using micro-PIV of the effect of microRNA-1 deficiency on motility inCaenorhabditis elegans

Ravikumar

Fedrizzi

Prabhakar

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…The Hamiltonian is a scalar function governing the timeindependent dynamics resulting from the mechanics of the worm's body, while C(Q i , P i , ψ(t)) encapsulates the time-dependent neuromuscular control forces due to interaction of worm's body with the environment, proprioceptive feedback and neural processing of various sensory stimuli ψ(t). Dynamics based on Hamiltonian structure are often associated with optimality and conservation laws and multiple efforts have reported quantities that remain roughly constant across a range external loads during C. elegans locomotion, such as the normalized wave length of the body wave, angle of attack, bending power, and the phase relationship between the muscle activity and body curvature [94][95][96][97][98]. Following the example of thermostatted dynamics (designed to capture constant temperature dynamics, see e.g.…”

Section: Discussionmentioning

confidence: 99%

Capturing the Continuous Complexity of Behavior inC. elegans

Ahamed¹,

Costa

Stephens

2019

Preprint

View full text Add to dashboard Cite

Animal behavior is often quantified through subjective, incomplete variables that may mask essential dynamics. Here, we develop a behavioral state space in which the full instantaneous state is smoothly unfolded as a combination of short-time posture dynamics. Our technique is tailored to multivariate observations and extends previous reconstructions through the use of maximal prediction. Applied to high-resolution video recordings of the roundworm C. elegans, we discover a lowdimensional state space dominated by three sets of cyclic trajectories corresponding to the worm's basic stereotyped motifs: forward, backward, and turning locomotion. In contrast to this broad stereotypy, we find variability in the presence of locally-unstable dynamics, and this unpredictability shows signatures of deterministic chaos: a collection of unstable periodic orbits together with a positive maximal Lyapunov exponent. The full Lyapunov spectrum is symmetric with positive, chaotic exponents driving variability balanced by negative, dissipative exponents driving stereotypy. The symmetry is indicative of damped, driven Hamiltonian dynamics underlying the worm's movement control.

show abstract

“…In this case the damping of the micropipette cantilever by hydrodynamic drag forces remains negligible, and forces can be directly recovered from the cantilever deflection and its static spring constant. In the context of microbial propulsion, such mi-cropipette force sensors have been applied successfully to the millimetre-sized nematode C. elegans [37][38][39], which has a typical beating frequency of about 2 Hz only [37]. Many flagellated and ciliated micro-swimmers, however, operate at much higher frequencies.…”

Section: Introductionmentioning

confidence: 99%

Dynamic force measurements on swimming Chlamydomonas cells using micropipette force sensors

Böddeker

Karpitschka

Kreis

et al. 2020

J. R. Soc. Interface.

View full text Add to dashboard Cite

Flagella and cilia are cellular appendages that inherit essential functions of microbial life including sensing and navigating the environment. In order to propel a swimming microorganism they displace the surrounding fluid by means of periodic motions, while precisely-timed modulations of their beating patterns enable the cell to steer towards or away from specific locations. Characterizing the dynamic forces, however, is challenging and typically relies on indirect experimental approaches. Here, we present direct in vivo measurements of the dynamic forces of motile Chlamydomonas reinhardtii cells in controlled environments. The experiments are based on partially aspirating a living microorganism at the tip of a micropipette force sensor and optically recording the micropipette's position fluctuations with high temporal and sub-pixel spatial resolution. Spectral signal analysis allows for isolating the cell-generated dynamic forces associated to the periodic motion of the flagella from background noise. We provide an analytic elasto-hydrodynamic model for the micropipette force sensor and describe how to obtain the micropipette's full frequency response function from a dynamic force calibration. Using this approach, we find dynamic forces during the free swimming activity of individual Chlamydomonas reinhardtii cells of 23 ± 5 pN resulting from the coordinated flagellar beating with a frequency of 51 ± 6 Hz. This dynamic micropipette force sensor (DMFS) technique generalises the applicability of micropipettes as force sensors from static to dynamic force measurements, yielding a force sensitivity in the piconewton range. In addition to measurements in bulk liquid environment, we study the dynamic forces of the biflagellated microswimmer in the vicinity of a solid/liquid interface. As we gradually decrease the distance of the swimming microbe to the interface, we measure a significantly enhanced force transduction at distances larger than the maximum extend of the beating flagella, highlighting the importance of hydrodynamic interactions for scenarios in which flagellated microorganisms encounter surfaces.

show abstract

The effects of viscosity on the undulatory swimming dynamics of C. elegans

Cited by 25 publications

References 36 publications

Experimental investigation using micro-PIV of the effect of microRNA-1 deficiency on motility inCaenorhabditis elegans

Experimental investigation using micro-PIV of the effect of microRNA-1 deficiency on motility inCaenorhabditis elegans

Capturing the Continuous Complexity of Behavior inC. elegans

Dynamic force measurements on swimming Chlamydomonas cells using micropipette force sensors

Contact Info

Product

Resources

About