Augmented Reality Rodent Behavioral Apparatus

This apparatus, termed the Instantaneous Cue Rotation (ICR) arena, was designed for performing behavioral experiments with rats. It features a circular track with a 1.4 m diameter that rats traverse. Four short-throw projectors positioned around the apparatus project visual cues onto the 68 cm tall cylindrical walls, which are composed of FlexGlass® for rear projection. The entire assembly is suspended from ceiling-mounted U-Channel tracks in a 4 m x 4 m room. The apparatus is primarily constructed from 80/20® extruded aluminum, CNC-milled acrylic, and Sintra® PVC foam board. The base of the track can be lowered for easy cleaning. A mobile feeder robot (featured as another uploaded project) tracks the rat and delivers food rewards. Efforts were made to eliminate non-visual orienting cues, with structural symmetry and continuous white noise masking auditory and olfactory cues. The codebase I developed for this is extensive. Several Arduino Due microcontrollers are used to control the reward delivery and track the position of the rat. The system is integrated with a Neuralynx Digital Lynx SX data acquisition system for real-time positional tracking and synchronous timestamp storage. The mobile feeder is wirelessly controlled via XBee-PRO RF modules, with all peripheral components powered by a LiPo battery. Custom C++ and C# scripts handle wireless communication, motor control, and tracking data processing, while Matlab scripts are used for front-end control, data processing, and visual cue management. For additional details, see the published methods manuscript, which features this system: Lester, A. W., Kapellusch, A. J. & Barnes, C. A. A novel apparatus for assessing visual cue-based navigation in rodents. Journal of Neuroscience Methods 338, 108667 (2020).