Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Animals exhibit "emotions" such as pleasure, discomfort, and motivation in response to external stimuli. Emotions are not merely subjective reactions; they serve as essential systems for survival and social adaptation, influencing decision-making and behavior. While emotions have traditionally been considered to be determined by the brain, recent findings suggest that internal states of peripheral organs, such as changes in heart rate and gut microbiota, also influence emotional responses. These findings highlight the need to examine not only the brain but also peripheral organs in understanding emotions. However, the precise mechanisms by which information from peripheral organs is transmitted to and processed by the brain, ultimately leading to emotions, remain unclear. Addressing this question requires a comprehensive investigation of the brain, peripheral organs, and emotional responses.

To tackle this challenge, we have developed a unique physiological recording system, utilizing custom-built electrodes designed with 3D printing and electronic engineering. These electrodes are implanted in rodents, allowing us to comprehensively record signals from the brain and peripheral organs during free behavior. By analyzing large-scale physiological data on neural and peripheral organ activity associated with emotional responses, we aim to uncover the mechanisms by which peripheral organs contribute to emotions.