Microfluidics-Enabled Simultaneous Imaging of Neural Activity and Behavior in Chemically Stimulated, Head-Fixed C. elegans

Understanding how the brain processes sensory information and produces appropriate behavior is a fundamental question in neuroscience. In this study, we developed a novel microfluidic device that allows for simultaneous observation of neural activity and behavior in Caenorhabditis elegans (C. elegans) during chemosensory stimulation. Traditional methods often involve trade-offs between high-resolution neuronal imaging, behavioral recording, and the ability to apply chemical stimulation. Our innovative design overcomes these limitations by immobilizing the worms head, stabilizing neuronal imaging, while allowing the posterior portion of the body to move freely, enabling the study of naturalistic behaviors during chemical stimulation. We applied this device to investigate how C. elegans responds to both attractive and aversive chemical cues. By correlating neural activity with observed behavior, we identified neurons and whole-brain dynamics associated with specific movements. Our results demonstrate that providing the worm with greater freedom of movement results in more naturalistic neuronal and behavioral responses to stimuli, compared to fully immobilized setups. This new tool offers a powerful approach for studying how sensory information is processed in the C. elegans nervous system to generate behavior, with potential applications in other model organisms. Its versatility and ease of operation make this device broadly applicable for studying how neural circuits drive behavior and decision-making in complex environments.