Understanding how brain activity gives rise to behavior is a central challenge in neuroscience. Our research combines advanced optical imaging, quantitative behavioral experiments, and computational approaches inspired by statistical physics to investigate how large populations of brain cells coordinate their activity across space and time. While most brain-wide imaging experiments require animals to remain immobilized or head-fixed, studying neural dynamics during natural behavior is essential to understand how the brain continuously interacts with its environment. Moreover, growing evidence suggests that glial cells, long considered primarily as supporting elements, actively participate in the regulation of neuronal activity and brain states. The small size and optical transparency of Danionella fish offer a unique opportunity to investigate the interplay between neuronal and glial dynamics in a freely behaving adult vertebrate. This internship aims to further develop our large-scale behavioral tracking arena, in which a motorized camera continuously follows a freely swimming fish. The objective is to extend this platform to enable simultaneous brain-wide recordings of neuronal and glial activity during natural locomotion and exploration. The ultimate goal is to establish a platform capable of simultaneously monitoring brain-wide neuronal and glial activity while adult Danionella explore a large environment freely.