A new study from Yale and the University of Connecticut has identified how specific neural connections help animals process sensory information and make appropriate decisions, using a microscopic worm as their model organism. The findings, published in Cell, detail how electrical connections between neurons act as specialized filters that help animals respond appropriately to their environment.
The research team focused on C. elegans, a tiny worm that can learn temperature preferences and navigate accordingly. These worms use two distinct behaviors to reach their preferred temperature: moving across temperature gradients and tracking specific temperatures once they’re in the right range.
“Altering this electrical conduit in a single pair of cells can change what the animal chooses to do,” explains Daniel Colón-Ramos, the Dorys McConnell Duberg Professor of Neuroscience and Cell Biology at Yale School of Medicine and corresponding author of the study.
The researchers identified electrical connections between specific neurons, called AIY neurons, that help control the worm’s movement decisions. These connections, formed by a protein called INX-1, act as sophisticated filters that allow the worms to ignore minor temperature variations while focusing on larger changes that guide them toward their preferred temperature.
When these electrical connections are disrupted, the neurons become overly sensitive to small temperature changes. “It would be like watching a confused bird flying with its legs extended,” Colón-Ramos said. “Birds normally extend their legs prior to landing but were a bird to extend its legs in the incorrect context it would be detrimental to its normal behavior and goals.”
The study reveals that worms lacking the INX-1 protein respond abnormally to minor temperature fluctuations, becoming trapped in temperature-tracking behavior even when they should be moving across temperature gradients toward their preferred temperature.
These findings extend beyond worm behavior. Similar electrical connections exist in other animals, including humans, suggesting broader implications for understanding how nervous systems process sensory information. “Scientists will be able to use this information to examine how relationships in single neurons can change how an animal perceives its environment and responds to it,” Colón-Ramos said.
The researchers note that similar neural configurations appear in the human retina, where cells called amacrine cells use electrical connections to help our eyes adapt to changes in light. This suggests that the principle of using electrical connections to filter and process sensory information may be widespread across species.
The study demonstrates that these neural connections don’t simply transmit information—they actively help animals interpret their environment and make appropriate decisions. By understanding these fundamental mechanisms, scientists may gain new insights into how nervous systems process information to guide behavior across the animal kingdom.