The animal brain is the most complex information processing system in any living organism. The goal of our research is to elucidate the mechanisms of information processing in the brain and neural circuits. Information about the external environment obtained through the sensory organs is processed in the neural circuits in combination with internal states such as memory, leading to the generation of appropriate behavior. Comprehensive measurement of the dynamics of neural activity along with behavior and quantitative analysis of the relationship between them are necessary for elucidating the operating principles. The nematode C. elegans, which we use in our research, has a well-characterized nervous system and wiring, making it an ideal organism for such analysis. We have developed a microscope that automatically tracks freely moving nematodes and measures whole-brain neural activity, and we are conducting comprehensive measurements of time-series data on neural activity and behavior. We are also working on mathematically modeling neural activity and behavior to quantitatively predict them, as well as applying optogenetic perturbations to verify their effects. We are actively developing cutting-edge technologies such as genome editing and single-cell gene expression analysis. Through this research, we aim to cultivate scientists who can integrate biological experiments and informatics analysis.