The mechanisms of drug-induced responses in C. elegans

This is a guest post from Dr. Maria Cambraia Guimaro, Assistant Director and Research Mentor for the STEM BUILD program at the University of Maryland, Baltimore County (UMBC), and from Naafia Thangalvadi, Caroline Moore and Surabhi Bhat, peer mentors from the STEM BUILD program at UMBC. Learn more about STEM BUILD at

The STEM BUILD program at UMBC is an NIH-funded training program designed to diversify the biomedical and behavioral sciences workforce. Trainees receive extensive support in research, career development, ethics instruction, and science communication. I am an instructor and research mentor for this program, and our team is always looking for opportunities to offer authentic research experience for our students. Every year, we offer an eight-week summer internship that focuses on transfer students from collaborating institutions and is designed for students interested in pursuing a four-year degree in biomedical and behavioral sciences. Most of our students have never had the opportunity to conduct research projects before attending our internship program, and this program is built up to strengthen their science skills and identity. 

Peer mentors Caroline and Surabhi training the summer interns on how to “chunk” the worms.

Our summer program follows a Course-based Undergraduate Research Experience (CURE) structure where students work as teams under the guidance of research mentors and peer-mentors (junior or senior undergraduate students with previous research experience).

This year, the research topic for our summer experience was “The mechanisms of drug-induced responses in C. elegans”. Drug addiction has a huge impact on society, and animal models are essential to test new treatments and understand the basic mechanisms underlying addiction. The nematode Caenorhabditis elegans can be a useful model to understand drug-induced behavior in humans. This worm possesses a genome with homologs of about two-thirds of all human disease genes, a conserved neurobiological system, and a rapid rate of development.

The interns’ projects focused on better understanding how genetics influences the interaction between drugs and behavior in C. elegans and how this might relate more generally to humans. Students gained experience in a variety of techniques used to assess behavioral responses and to assess genes that could be involved in the effects of ethanol and other drugs.

NGM plates were prepared with different drugs (nicotine and caffeine) or high concentration of sugars. Worms were transferred to these plates to test the effect of these substances. Tolerance, toxicity and chemotaxis assays adapted from the EDVO-kits were conducted with these pre-treated worms.

The selected peer mentors for this summer spent the previous spring semester establishing experience in using the C. elegans model and piloting research projects. During the summer, they trained and provided guidance to the summer interns for eight weeks. For the peer mentors’ training sessions in the spring, we used the Edvotek kits for experiments with C. elegans (Edvo-Kit #851 Effects of Alcohol on C. elegans, #852 Chemotaxis: The Science of Attraction in C. elegans, and #856 Environmental Toxicity Response in C. elegans). These kits provided different C. elegans strains and all the necessary reagents and protocols to rapidly familiarize our peer mentors with this new model. You can see below the feedback from our peer-mentors.

Peer mentors’ feedback

Peer Mentors Naafia, Surabhi and Caroline seeding the NGM plates.

Naafia Thangalvadi (Biochemistry and Molecular Biology Junior Undergrad at UMBC)

When we first started using the Edvotek Kits in January during the spring semester, it was a very surreal experience. Having been online for two years due to the pandemic, I hadn’t had the opportunity to do biology research. I had no experience going in about what C.elegans were and how they worked. I learned a lot from the information listed on the kits about the model organism and the mutant C. elegans we were able to use. It was interesting to separate the C. elegans and look at them under the microscope. We first started out using the ethanol model and counted the thrashes or movements of the nematodes. We then moved on to the chemotaxis model and tested if they were attracted to ethanol. 

After learning the basic use of the kits, we started to expand on them. Over the summer, we had to teach other students how to use the kits and the various experiments that came with them. From that we developed our own experiments. For example, my team’s project was about nicotine. We wanted to test if the C. elegans would be attracted to nicotine if they were pre-exposed to the substance. We later went on to present at our university’s summer research conference. Overall, the kits were very easy to use myself and teach others to use as well. The experiments were fun to conduct and yielded significant results when adding other conditions. A lovely experience! 

Caroline Moore (Biology Senior Undergrad at UMBC)

Serving as a peer mentor and teaching incoming students lab skills, these kits were a blessing. Incoming students often have little to no lab experience and the C. elegans kits provide a straightforward, yet energizing first lab experience. My students not only learned how to properly care for the C. elegans and use proper sterile technique, but also how to conduct experiments on a model organism. We were also able to create several different experimental conditions with the kit, including testing for ethanol, caffeine, nicotine, and glucose tolerance. We were also able to perform a variety of types of experiments, including both tolerance and chemotaxis assays. Overall, this kit provided a well-rounded, diverse first lab experience that allowed my students to expand on a variety of lab skills. 

Surabhi Bhat (Biology Senior Undergrad at UMBC)

I served as a Peer Mentor this summer for aspiring students in research, and the Edvotek kits we used during this time served as a vital resource for our projects. The entirety of our research experience consisted of working with C. elegans: performing tolerance assays, chemotaxis assays, and introducing them to different substances. In each of these tests, the Edvotek kits helped kickstart our students’ understanding of how to deal with the C. elegans and how to properly set up materials in order to perform a successful experiment. With the assistance of the kits and the matching guides, they were able to go from learning pipetting one day to chunking C. elegans plates the next. Having ordered steps with matching equipment for each helped minimize the hassle that comes with starting a new experiment, allowing for the students to stay focused on the excitement and knowledge that comes with learning something new.

Communicating Science

Another goal from our summer internship was that peer mentors and summer interns could develop their writing and oral presentation skills and be able to communicate their scientific findings. While performing their experiments and conducting data analysis, our students were able to learn how to present their results in different formats. Several ideas on how to conduct their analysis and create graphs and flowcharts for their adapted protocols came from the Edvotek kits. At the end of the summer experience, our interns presented their summer research as a virtual talk in the BUILD a Bridge to STEM Summer Research Internship Research Symposium and also developed an abstract and a poster that were presented at the 2022 Summer Undergraduate Research Fest (SURF) at UMBC. 

Peer mentor Caroline preparing chemotaxis plates.
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