Amplitude-modulated sinusoidal microchannels for observing adaptability in C. elegans locomotion

Abstract

In this paper, we present a movement-based assay to observe adaptability in Caenorhabditis elegans locomotion behavior. The assay comprises a series of sinusoidal microchannels with a fixed wavelength and modulating ͑increasing or decreasing͒ amplitude. The channel width is comparable to the body diameter of the organism. Worms are allowed to enter the channel from the input port and migrate toward the output port. Within channel sections that closely match the worm's natural undulations, the worm movement is relatively quick and steady. As the channel amplitude increases or decreases along the device, the worm faces difficulty in generating the propulsive thrust, begins to slow down and eventually fails to move forward. A set of locomotion parameters ͑i.e., average forward velocity, number and duration of stops, range of contact angle, and cut-off region͒ is defined for worm locomotion in modulated sinusoidal channels and extracted from the recorded videos. The device is tested on wild-type C. elegans ͑N2͒ and two mutants ͑lev-8 and unc-38͒. We anticipate this passive, movement-based assay can be used to screen nematodes showing difference in locomotion phenotype.

On-chip analysis of C. elegans muscular forces and locomotion patterns in microstructured environments

“…Values indicate nematode crawling behaviour comparable to data reported for smooth crawling. 35,44 ments. This variation in the undulation frequency verifies that the worm responds to different geometric constraints imposed by the pillar arrangement through changes in the period at which it flexes its dorsal-ventral body wall muscles.…”

“…In particular, a series of sinusoidal microchannels with varying amplitudes and wavelengths was used to match the worm sinusoidal movement. 35 Their suggested methods can be used as a screening system for locomotion phenotypes. As previously mentioned, C. elegans locomotion is highly dependent of its environment.…”

An automated microfluidic system for screening Caenorhabditis elegans behaviors using electrotaxis

“…8,9,[12][13][14][15][16][17] Moreover, microfluidic devices can be automated to handle single or a population of C. elegans in a high-throughput fashion, which enables large-scale assays such as drug and genetic screens. [15][16][17][18][19][20][21][22] In previous work from our group, we designed a simple microfluidic device to examine the swimming behaviors of C. elegans under electric fields, termed electrotaxis, and demonstrated that changes in movement are reliable indicators of neurodegeneration and harmful effects of toxic chemicals on C. elegans health. [23][24][25] However, the inherent manual operation of the devices makes the screening process labor intensive and time consuming, which limits largely the practical application of the method.…”

Microfluidics-enabled method to identify modes of Caenorhabditis elegans paralysis in four anthelmintics

“…Crawling is the undulatory, sinusoidal movement of a worm that results in forward or backward locomotion. 33 Curling, as defined earlier, occurs when the worm's head touches or overlaps its tail. Flailing happens when a worm oscillates its body in half waves about a fixed location and is an unusual swimming-like behavior we observed in 0.8% agarose gel.…”