Positive control validation of Morris water maze and Biel water maze – Learning and memory assessment testing strategies for weanling and adult rats

EUROTOX Congress 2025 -- The U.S. EPA OPPTS 870.6300 Test Guideline (TG), the OECD 426 TG, and potential additions to OECD 443 TG emphasize the need for test batteries assessing learning and memory (L&M) function in rodents at weaning and adulthood. While cognitive testing methods are well established for adult animals, assessing L&M in younger animals presents challenges due to their physical immaturity, sensitivity to handling, and heightened stress levels, resulting in greater data variability. This work was performed in order to validate and optimize the Morris water maze (MWM) and Biel water maze (BWM) as options for allocentric and egocentric L&M procedures. This demonstrated that the L&M  test procedure at Labcorp can detect chemically induced changes and therefore its suitability for use on regulatory DART studies.