Assessment of motor activity in rodents: Positive control validation using the VivaMARS Mobile Activity Rack System (MARS)

EUROTOX Congress 2025 -- Motor activity (MAT) is a key endpoint in safety assessment studies, including toxicity, neurotoxicity and developmental and reproductive toxicity (DART) studies. The EPA OPPTS 870.6200 test guideline (TG) defines motor activity as “any movement of the experimental animal” and along with the EPA OPPTS 870.6300, the OECD 424, 426, and 443 TG, states that MAT should be monitored by an automated activity system capable of detecting both increases and decreases in activity, with evidence from positive control data. Many studies have high numbers of animals requiring testing at a specific postnatal day (PND), creating logistical challenges. Testing should be conducted at similar time of the day for all animals to minimize variability in data. This work was performed in order to validate the VivaMARS Mobile Activity Rack System (MARS), a new high-throughput activity solution, using positive control compounds, to demonstrate that MARS is capable of detecting chemically induced changes and therefore its suitability for use in regulatory safety assessment studies.