LEARNING AND MEMORY IN THE SAMP8 MOUSE

The SAMPs (P8) mouse strain develops deficits in learning and memory r elatively early in its lifespan. This review provides an overview of t he age-related changes that occur in P8 mice. Behavioral studies with Ps mice show impaired acquisition and retention as early as 4 months o f age. Deficits in acquisition and retention occur with both aversive and appetitive training tasks. Anatomical studies have detected a numb er of age-related changes that occur in the central nervous system of P8 mice. The age-related increase in amyloid beta protein is well corr elated with the age-related decline in learning and memory. Antibody t o amyloid beta protein injected prior to training alleviated impaired acquisition and retention, whereas post-training injections alleviated retention deficits in older P8 mice. Biochemical studies have detecte d numerous age-related changes with reduced NMDA receptor activity mos t closely related to impaired learning and memory in P8 mice. Pharmaco logical studies have found age-related functional changes in the abili ty of drugs to improve memory processing in P8 mice in the septum and the hippocampus. The specific pattern of pharmacological changes and t he inferred change in neurotransmitter activity suggest that age-relat ed impairment in memory processing may be due to impaired septohippoca mpal interactions. The proposal that P8 mice may be a useful model for studying the early phases of age-related dementia of the Alzheimer ty pe, while still requiring considerable study, seems reasonable. Publis hed by Elsevier Science Ltd.