Foraging and Hunting Behavior in Rats

Three to 5 months old Long-Evans female rats were trained sequentially to forage and hunt virtual elements of a projected display in exchange for water rewards. The behavioral paradigm consists of a custom built arena made of structural framing components (Bosch Rexroth, DE). The floor of the arena is a rear-projection screen made out of a frosted acrylic panel. In order to compensate for the short-throw distance, the projected image is reflected off a mirror positioned below the arena floor. Video was recorded using a high-speed monochrome video camera (Flea3, Point Gray, CA) equipped with a visible light cutoff filter (R72, Hoya, JP) and analyzed in real-time using Bonsai. Infrared LED strips were positioned at the bottom of the arena in order to illuminate the floor through the diffuser, allowing for the tracking of the animal without contamination from the visual stimulus. Animals were first conditioned to a tone as a secondary reinforcer and then subsequently trained to either touch the light presented at random locations (foraging) or pursue a moving spot (hunting). Performance, monitoring and control of the behavior box was done using an Arduino board (Micro, Arduino, IT) and a Bonsai reactive state machine.