To understand circuit mechanisms underlying naturalistic behavior, it is essential to simultaneously record neural activity in multiple brain regions and correlate it with behavior. We report a multi-region miniscope that uses four highly flexible and light-weight imaging fiber bundles (IFB) and enables imaging of up to 4 brain areas in freely behaving subjects. Transgenic animals or virus expression is used to express a cell-type specific green fluorescence tag. Up to four GRIN Lens-Connectors (GLCs) can be surgically implanted into the brain regions of interest. The GLCs are designed with the capability of implantation at various angles and a focus-lock mechanism. This allows imaging hard-to-reach brain regions of birds, rodents and juvenile animals. During an imaging-behavior session, the IFBs are connected to the implanted GLCs. The IFBs transmit the illumination light from the LED source (470nm +/-12nm) to the implanted GLCs. Each GLC forms the image of neurons above its distal end from the brain. The same illumination IFB then picks up this image and transmits it to the camera. The use of IFBs keeps all optics away from the head of the animal, enabling light-weight implants (total <1.5gr) with small footprints so four can fit on the head of a mouse. We report imaging 100s of neurons in the Hippocampus, Amygdala and Medial Pre-Frontal Cortex in open field and swimming paradigms. We present a software enabling processing of brain movies and neuronal trace extraction. This system is a powerful tool for neuroscientists to study intraregional and interregional neuronal circuits.