The Effect of Internalized Paramagnetic Nanoparticles on Caenorhabditis elegans Locomotion in the Presence of Magnetic Field

Figure 5

Locomotion features and their metrics, as they have been quantified for all four groups of worms tested in the absence (OFF state) or in the presence (ON state) of external magnetic field (MF). For each group, tested worms were tracked in three independent experiments conducted on three experimental days (OFF1/ON1, OFF2/ON2, OFF3/ON3). (a–h) (all) superpanels eight locomotion features have been quantified: (a) bend count, (b) , (c) , (d) , (e) forward/backward motion ratio, (f) stay ratio, (g) path curvature, and (h) range. Group 100 (grey plots): fed on E. coli OP50 mixed with 100 nm-diameter iron core paramagnetic particles, n = 33 (n₁ = 13, n₂ = 11, n₃ = 9); Group 1 (pink plots): fed on E. coli OP50 mixed with 1 μm-diameter paramagnetic particles, n = 32 (n₁ = 14, n₂ = 10, n₃ = 8); Group 40 (lime plots): fed on E. coli OP50 mixed with 40 nm-diameter iron core paramagnetic particles, n = 25 (n₁ = 10, n₂ = 7, n₃ = 8); Group C: control animals, fed on plain food source E. coli OP50, n = 30 (n₁ = 11, n₂ = 10, n₃ = 9). Graphs compare ON and OFF results from each experiment (a–h, left panels) and from all three experiments combined (a–h, right panels). Subpanels of rows a1–h1 display results for Group 100, rows a2–h2 results for Group 1, rows a3–h3 results for Group 40, and rows a4–h4 for Group C. Comparisons were made by applying Student’s t-test (unpaired for individual experiments, paired for combined data); any difference was considered statistically significant when , only statistically significant differences are shown. We consider a locomotion feature to be affected by internalized paramagnetic particles in the presence of MF only when there is a statistically significant difference detected on at least two experiments and when comparing combined data. Therefore, only speed (panel b1), forward/backward motion ratio (panel e1) and stay ratio (panel f1) for Group 4 nematodes are significantly affected.

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