Microfluidic-based electrotaxis for on-demand quantitative analysis of Caenorhabditis elegans' locomotion

Area of Science:

• Neuroscience
• Biomedical Engineering
• Genetics

Background:

• Caenorhabditis elegans is a model organism for studying neurodegenerative diseases like Parkinson's disease (PD).
• Conventional screening methods for neuroprotective agents are time-consuming and may overlook locomotion defects.
• Locomotion is a critical parameter for movement disorders, yet often ignored in traditional assays.

Purpose of the Study:

• To develop a novel microfluidic system for automated, high-throughput screening of C. elegans.
• To utilize electric fields to control and quantify C. elegans locomotion for assessing neuronal function.
• To investigate the electrotactic response of C. elegans to various electric field stimuli.

Main Methods:

• A microfluidic device was engineered to apply controlled electric fields (DC, pulsed DC, AC) to C. elegans.
• Locomotion was quantified using parameters like speed, bending frequency, and reversal time.
• The system was used to assess the impact of neuronal defects and age on electrotaxis.

Main Results:

• A Direct Current (DC) field successfully induced electrotaxis (movement towards the cathode) in C. elegans.
• Altered electrotactic responses were observed in worms with defects in dopaminergic and sensory neurons.
• The electrotactic response varied with age, with young adults exhibiting faster movement at lower field strengths.
• Pulsed DC fields induced electrotaxis, while AC fields immobilized the worms.

Conclusions:

• The microfluidic electrotaxis assay provides a rapid, automated, and quantitative method for screening.
• This system facilitates high-throughput genetic and chemical screens for factors impacting neuronal function and viability.
• The ability to sort worms by age and phenotype using this technology opens new avenues for research.