Senescence-Accelerated Mouse SAM-P/8 Shows Spontaneous Age-Related Impairment of Ability of Acquisition of Learning and Memory: An Animal Model of Disturbances in Recent Memory with Aging

Abstract

Several pairs of AKR strain mice were donated to our laboratory by the Jackson Laboratory(Bar Harbor) in 1968. We continued the sister-brother mating of these mice and became aware of some litters which showed a moderate to severe loss of action, hair loss, skin coarseness, and a shortened life span. We selected and maintained 6 substrains with severe exhaustion as accelerated senescence prone(SAM-P/l,-P/2,-P/3,-P/4,-P/6,-P/8) and 3 substrains with normal aging process as accelerated senescence resistant(SAM-R/1,-R/2, -R/3).¹ Judging from findings in the survivors and for Gompertzian function of the growth pattern, the aging pattern in this SAM model seems to relate to an accelerated senescence rather than to premature aging. Recently, SAM-P/8 was reported to show age-related learning and memory deficits in passive avoidance performance under specific pathogen-free conditions.² In this present study, we examined age-related changes in memory of SAM-P/8 under conventional conditions and found that SAM-P/8 is a pertinent model for researching disturbances of recent memory with aging in animals and humans.