Flood J F, Morley J E
Geriatric Research Education and Clinical Center (GRECC), VA Medical Center, St. Louis, MO 63106.
Neurobiol Aging. 1993 Mar-Apr;14(2):153-7. doi: 10.1016/0197-4580(93)90091-o.
An inbred strain has been developed which exhibits some characteristics of aging in mice as young 6 months of age. The strain was designated "Senescence Accelerated Mouse" (SAM). A subline of the SAM strain, P/8, has an early onset of impaired learning in appetitive and aversive training tasks. Simple aversive and appetitive tasks were learned normally up to 12 months of age, whereas more difficult tasks detected impairment as early as 6 months of age while the mice still had good general health. Comparable impairment of learning and memory in C57BL/6Nnia mice was not detected until about 24 months of age which is near the end of the strain's lifespan when general health declines. In the present study, we report age-dependent impairment of acquisition and retention for footshock avoidance conditioning. Long-term (1 week) but not short-term (1 h) retention was adversely effected by aging. In 12-month-old P/8 mice, practicing the avoidance response (overtraining) did not alleviate the impairment of long-term memory processing.
已经培育出一种近交系，该近交系在6个月大的幼龄小鼠中表现出一些衰老特征。该品系被命名为“衰老加速小鼠”（SAM）。SAM品系的一个亚系P/8，在食欲性和厌恶性训练任务中出现学习障碍的时间较早。简单的厌恶性和食欲性任务在12个月大之前都能正常学习，而更困难的任务早在6个月大时就检测到了损伤，此时小鼠的整体健康状况仍然良好。在C57BL/6Nnia小鼠中，直到大约24个月大时才检测到类似的学习和记忆损伤，此时该品系的寿命接近尾声，整体健康状况下降。在本研究中，我们报告了足部电击回避条件反射的获得和保持存在年龄依赖性损伤。长期（1周）而非短期（1小时）保持受到衰老的不利影响。在12个月大的P/8小鼠中，练习回避反应（过度训练）并不能减轻长期记忆处理的损伤。
