Artificial dirt: microfluidic substrates for nematode neurobiology and behavior

Area of Science:

• Neurobiology
• Biomedical Engineering
• Developmental Biology

Background:

• The nematode Caenorhabditis elegans (C. elegans) is a key model organism in neurobiology due to its simple nervous system (302 neurons).
• Current laboratory substrates (e.g., agarose surfaces) limit C. elegans research by not mimicking natural environments, hindering stimulus delivery, and impeding high-resolution imaging.
• Existing methods restrict optophysiology and detailed neuronal studies.

Purpose of the Study:

• To develop novel microfluidic devices for C. elegans research that overcome limitations of traditional agarose substrates.
• To create an environment that better reflects the natural habitat of C. elegans, facilitating more complex behavioral studies.
• To enhance compatibility with advanced imaging techniques for neuronal activity recording.

Main Methods:

• Design and fabrication of agarose-free, micron-scale microfluidic chambers and channels for C. elegans.
• Development of a device mimicking a moist soil matrix for efficient fluid-borne stimulus delivery.
• Creation of sinusoidal channels to precisely control worm movement and trajectory.
• Ensuring device transparency and thin profiles for high-resolution microscopy and optophysiology.

Main Results:

• The new microfluidic devices allow C. elegans to crawl naturally within micron-scale chambers and channels.
• One device successfully mimics a soil matrix, enabling rapid delivery of fluid-borne stimuli.
• Sinusoidal channels effectively regulate the waveform and trajectory of crawling worms.
• The devices' transparency and thinness are compatible with high-resolution neuronal imaging and optical recording.

Conclusions:

• The developed microfluidic devices represent a significant advancement for C. elegans neurobiology and behavior studies.
• These agarose-free systems address key limitations of current experimental setups, enhancing research capabilities.
• The technology is expected to accelerate the understanding of the neuronal basis of behavior in C. elegans.