Operant House: A Versatile Open-Source Platform for Automated Operant Conditioning Testing of Mice in Home Cages

Operant conditioning is a valuable method for studying cognitive functions, yet its adoption is limited by low throughput, labor intensity, and high costs. Here, we developed "Operant House," a low-cost, programmable device featuring a touchscreen, retractable levers, and a water reward port, designed for flexible, automated operant conditioning tasks. To validate its utility, we implemented two protocols to assess working memory in mice: a delayed non-match-to-position test and a two-choice spatial discrimination test. Using these protocols, we examined a mouse model of Alzheimers disease carrying familial Alzheimers disease-associated amyloid precursor protein mutations. Results revealed significant working memory deficits as early as 5 months of age. These findings highlight the Operant House as a cost-effective, high-throughput platform for evaluating higher cognitive functions in mice, offering an accessible tool for investigating models of neurological and neuropsychiatric disorders.