Fiber photometry monitors neuronal activity in the brain of freely moving behaving animals that helps correlate brain functioning with animal behavior. It uses implanted fiber-optic cannula to deliver excitation light to a group of neurons labeled with genetically encoded calcium indicators and detect their calcium-related fluorescence fluctuations. While it lacks the cellular/spacial resolution of a miniature fluorescence microscope, fiber photometry uses a relatively simple setup to record fluctuations in the calcium activity of a group of neurons in behaving animals. A smaller cannula's fiber diameter is better suited for deep tissue neuronal activity monitoring than a somewhat larger lens of miniature fluorescence microscopes. Our Fiber photometry systems are easily customized to fit different fluorescent markers and experiment configurations. All those varieties are supported with a user-friendly Doric Neuroscience Studio software package.