New Haven, Conn. – Researchers at Yale University and the University of Connecticut have unveiled significant insights into how animal brains process sensory information and make decisions. Published in the journal Cell, the study highlights the critical function of electrical synapses in filtering sensory data, allowing animals to make context-appropriate choices.
The research focuses on the nematode C. elegans, which serves as a powerful model for understanding neural mechanisms of decision-making. The worms exhibit behaviors that demonstrate their ability to navigate temperature gradients by employing two strategies: gradient migration towards preferred temperatures and isothermal tracking when near their desired range.
The scientists discovered that a specific type of connection, known as electrical synapses, plays a pivotal role in this process. These synapses, mediated by the protein INX-1, connect AIY neurons responsible for locomotion decisions. Daniel Colón-Ramos, a professor at Yale, noted, "Altering this electrical conduit in a single pair of cells can change what the animal chooses to do." This suggests that electrical synapses do not merely transmit signals but also act as sophisticated filters.
In normal conditions, these synapses help the worms ignore minor temperature fluctuations, enabling them to focus on significant changes in their environment. However, when INX-1 is absent, the worms become hypersensitive to small temperature variations, leading to misguided navigation.
Colón-Ramos likened this to a bird extending its legs inappropriately while flying, which can hinder its ability to land effectively. The implications of this research extend beyond C. elegans, as electrical synapses are prevalent in the nervous systems of many animals, including humans.
Colón-Ramos emphasized the broader significance, stating, "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." This understanding could enhance knowledge of sensory processing and decision-making across various species.
Moreover, the study's findings might inform applications in fields such as neuroscience and artificial intelligence, where understanding sensory filtering and decision-making processes could lead to advancements in technology and treatment strategies.
The research team included co-lead authors Agustin Almoril-Porras and Ana Calvo, with contributions from several Yale and University of Connecticut researchers. The project received support from the National Institutes of Health, the National Science Foundation, and a Howard Hughes Medical Institute Scholar Award.