Related Experiment Video
Updated: Jul 15, 2026
Mechanical Conflict-Avoidance Assay to Measure Pain Behavior in Mice
Published on: February 18, 2022
Reversible AChE inhibitors in C. elegans vs. rats, mice
Paul C Melstrom1, Phillip L Williams
1Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA.
Abstract:
We are investigating whether Caenorhabditis elegans could be used as a screen for vertebrates by comparing the responses of components of its cholinergic system to well-characterized toxicants. We assessed whether C. elegans displays similar toxicity as rats and mice to reversible acetylcholinesterase (AChE) inhibitors, and sought to corroborate that the toxicity mechanism is the same. To determine relative potencies, movement-concentration curves were generated, 50th percentiles for movement were located, ranked and compared statistically to rat and mouse oral acute LD50s. The ranking was significantly correlated to rat and mouse rankings (alpha=0.05). We measured a concentration-dependent decrease in AChE activity correlating to a decrease in movement for each carbamate, suggesting that the mechanism of toxicity is the same. Finally, as seen in mammals, inhibition of AChE activity occurred before a movement decrease. The response of C. elegans to carbamate exposure shows significant correlation to rat and mouse data.
Insights
Caenorhabditis elegans responses to acetylcholinesterase (AChE) inhibitors correlate with vertebrate data. This study validates C. elegans as a model for vertebrate toxicological screening of AChE inhibitors.
Area of Science:
- Toxicology
- Neuroscience
- Model Organisms
Background:
- Acetylcholinesterase (AChE) inhibitors are widely used toxicants.
- Vertebrate models for toxicity testing are expensive and time-consuming.
- Caenorhabditis elegans offers a potential alternative for toxicological screening.
Purpose of the Study:
- To evaluate Caenorhabditis elegans as a model organism for vertebrate toxicity screening.
- To compare the toxicity of reversible AChE inhibitors in C. elegans to rats and mice.
- To confirm that the mechanism of toxicity is conserved between C. elegans and mammals.
Main Methods:
- Generated movement-concentration curves for C. elegans exposed to carbamates.
- Determined 50th percentiles for movement and ranked relative potencies.
- Statistically compared C. elegans toxicity rankings with rat and mouse oral acute LD50s.
- Measured AChE activity in response to carbamate exposure.
Main Results:
- C. elegans toxicity rankings showed significant correlation with rat and mouse rankings (alpha=0.05).
- A concentration-dependent decrease in AChE activity correlated with decreased movement in C. elegans.
- AChE inhibition preceded observable movement decrease, mirroring mammalian responses.
- C. elegans demonstrated conserved toxicity mechanisms for carbamate exposure.
Conclusions:
- Caenorhabditis elegans exhibits conserved toxicity mechanisms for AChE inhibitors compared to vertebrates.
- C. elegans serves as a valid and potentially cost-effective model for vertebrate toxicological screening.
- This study supports the use of C. elegans in assessing the toxicological impact of AChE inhibitors.
