Caenorhabditis elegans locomotion dynamics is affected by internally localized magnetic fields
C. elegans nematodes are a model organism used broadly to investigate the impact of environmental factors on physiology and behavior. Here, C. elegans with internalized paramagnetic nanoparticles were placed inside magnetic field to explore effects on locomotion. We hypothesize that internalized paramagnetic nanoparticles combined with external magnetic field affect C. elegans locomotion machinery. To test our hypothesis, we used young adult C. elegans fed on bacteria mixed with paramagnetic nanoparticles of 1 m, 100 nm and 40 nm diameter. The presence of nanoparticles inside the worms body (alimentary canal, body muscle) was verified by fluorescent and electron microscopy. A custom-made software was used to track freely moving C. elegans in the absence or presence of magnetic field sequentially for 200+200 sec. We used established metrics to quantify locomotion-related parameters, including posture, motion and path features. Key features of C. elegans locomotion (increased body bends and stay ratio, decreased range, forward movement, and speed along the magnetic field) were affected in worms with internalized nanoparticles of 100 nm and 1 m in the presence of magnetic field, in contrast to untreated worms. Our work contributes on clarifying the effect of internalized paramagnetic nanoparticles, combined with magnetic field, on C. elegans locomotion. Summary StatementC. elegans with internalized paramagnetic nanoparticles are placed inside magnetic field to explore effects on locomotion. Results support the potential of C. elegans to investigate the impact of the above environmental factors on behavior.