Calcium imaging is a powerful tool to explore communication in neural networks. The hypothalamus is the region of the brain that regulates functions such as reproduction, appetite, lactation, stress, or hydration. Understanding the orchestration of neural networks in this region is a fundamental question of neuroscience. Calcium imaging can be used and performed not only on dissociated cells and acute brain slices but also on living animals. To date, the ideal experimental setup to explore nutrient sensing in the hypothalamus is acute brain calcium imaging. The technique readily incorporates pharmacological tools, as it uses bath applications or patch puffing. The technique can also be coupled with electrophysiological recordings.Here is presented the technical protocol for calcium imaging on acute brain slices of mice hypothalami.