Learning and memory assessment in rodents: Testing strategies for weanling and adult rats

SOT 2024 -- The U.S. EPA OPPTS 870.6300 Test Guideline (TG), the OECD 426 TG and potential additions to OECD 443 study designs call for test batteries for assessing learning and memory (L&M) function in rodents around the time of weaning and at adulthood. While cognitive testing procedures are well established for adult animals, L&M testing in younger animals are challenging due to their physical immaturity, sensitivity to handling and low stress tolerance, which may impact and/or result in greater data variability. Therefore, it is imperative to conduct positive control validation studies with known phenotypic outcomes to validate equipment and optimize test procedures for a given behavior assay to get the most reliable and reproducible data in both stages of development.