P2.18. THE SWITCHBOARD TEST: A FLEXIBLE, LOW-COST PLATFORM FOR STUDYING SPATIAL MEMORY IN RATS DURING SEQUENTIAL INSTRUMENTAL TASKS
Ravindra Sahu1, Witold Żakowski2, Krzysztof Maćkiewicz1,2, Olga Polniak2, Daniel Wiśniewski3, Józef Kotus3, Johannes Niediek4, John P. Aggleton5, Shane M. O’Mara6, Maciej M. Jankowski1
1 BioTechMed Center, Multimedia Systems Department, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
2 Department of Animal and Human Physiology, Faculty of Biology, University of Gdansk, Gdansk, Poland
3 Multimedia Systems Department, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
4 Machine Learning Group, Technische Universität Berlin, Berlin, Germany
5 School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
6 Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
INTRODUCTION: Appetitive instrumental conditioning is widely used to shape animals’ associations between actions and outcomes under controlled conditions. When implemented in automated environments with more complex tasks, it enables the collection of high-resolution data across hundreds of trials, supporting fine-grained behavioral analysis.
AIM(S): To develop and validate a flexible operant conditioning setup for assessing spatial memory in rats.
METHOD(S): We present an automated, low-cost environment for studying spatial memory in rats. The setup supports training and testing of location- and sequence-specific responses, with adjustable parameters such as layout, sequence length, cues, timing, and reward size. The 64 × 64 cm open field features nine floor buttons (3 × 3 grid) and a single reward area. An Arduino and PC manage switches, the dispenser, feedback sound playback, and a 64-LED reward cue. The system is compatible with electrophysiology and DBS, offering a flexible tool for behavioral research.
RESULTS: Over several weeks, rats (n = 16) were gradually trained to memorize a target button-press sequence, which outlined a fixed spatial route within the arena. Each trial was self-initiated and, if successfully completed, ended with a distinct sound and a light cue, indicating reward delivery and signaling successful trial completion. Errors resulted in a distinct feedback sound and immediate termination of the trial. Upon activation, each switch in the target sequence triggered a unique sound from a set of complex natural sounds, such as those of crickets, small frogs, and dolphins, intended for further transfer of spatial memory to the auditory domain. In expert rats, removing all feedback sounds had a minimal effect.
CONCLUSIONS: Based on experimental data, we proposed a memory score calculation to generate learning curves, offering a sensitive metric of spatial memory performance. This study presents a novel approach to evaluating spatial memory within a flexible, dynamic operant conditioning framework.
FINANCIAL SUPPORT: This work was supported by the National Science Centre and the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 945339, Polonez Bis 3, project No. 2022/47/P/NZ4/03358; and by the Gdansk University of Technology, Platinum IDUB grant: 1/1/2024/IDUB/I.1B/Pt.