How roundworm olfactory neurons help sniff out clues for decision-making enabled with novel device

In the animal kingdom, a sense of smell is crucial for survival. Whether it’s detecting smoke or a potential meal, olfactory neurons play a critical role in directing animal behavior. Caenorhabditis elegans, a type of roundworm, uses olfactory neurons in both their heads and tails to navigate their environment and avoid predators.

Researchers are working to understand how these worms use their olfactory neurons when navigating chemical gradients, particularly when conflicting signals are received at the head and tail ends. This work helps researchers better understand olfactory perception and behavior, which, in turn, could enable insights into human olfactory responses in addiction, substance abuse, and more.

Karimi et al. developed a new microfluidic device that can simultaneously stimulate the head and tail of a roundworm while monitoring neural activity. The optimized device offers several advantages in experimentation, such as precise, high-resolution microscopy, a fast experimental setup, and simultaneous olfactory delivery to the head and tail. To test the device, experiments were conducted in two separate setups to ensure it would work well in different environments and laboratories.

“I am excited about the final product, of course, and that it provides new experimental possibilities,” said author Michael Krieg. “But I was also excited during the process because it provided training opportunities to junior colleagues and helped to solidify the microfluidic part in the lab.”

The authors want to eventually understand the fundamental neurobiology of how individual animals respond to conflicting stimuli. For this, they plan to expand the device’s capabilities for multimodal stimulus delivery by combining multiple stimuli such as olfactory, thermal, mechanical, and light stimuli.

Source: “Automated dual olfactory device for studying head/tail chemosensation in Caenorhabditis elegans,” by Shadi Karimi, Asaf Gat, Costanza Agazzi, Meital Oren-Suissa, and Michael Krieg, APL Bioengineering (2024). The article can be accessed at https://doi.org/10.1063/5.0187441 .