Molecular overexpression of extracellular superoxide dismutase increases the dependency of learning and memory performance on motivational state.
Molecular overexpression of extracellular superoxide dismutase increases the dependency of learning and memory performance on motivational state.
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细胞外超氧化物歧化酶的分子过度表达增加了学习和记忆表现对动机状态的依赖性。
DOI：
10.1023/a:1001947003299
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发表时间：
2000
影响因子：
2.6
通讯作者：
Crapo,JD
中科院分区：
文献类型：
--
作者：
Levin,ED;Brucato,FH;Crapo,JD
细胞外超氧化物歧化酶（EC-SOD）控制细胞外超氧化物的可用性，并似乎在控制细胞间信号转导中发挥作用。在此作用中，EC-SOD可对神经行为功能具有强有力的影响。在以前的研究中，我们发现EC-SOD的过度表达或表达不足都会显著损害小鼠在径向臂迷宫上的空间学习能力。在目前的研究中，EC-SOD在认知功能中的作用的神经行为性质被确定。EC-SOD过表达改变了学习记忆与动机状态的关系。在高动机状态（22-24小时的食物限制）或低动机状态（4-6小时的食物限制）下在径向臂迷宫中测试小鼠。在高动机状态下，EC-SOD过表达小鼠能够在径向臂迷宫中学习，尽管速度略低于野生型对照组。这与我们先前在低动机状态下进行的研究中EC-SOD过表达小鼠的学习失败形成对比。动机状态的变化并没有显着改变控制的学习率。同样，在后获得的记忆阶段的测试，EC-SOD过表达的小鼠显着低于对照组时，测试在低动机状态，但不是在高动机状态。与学习，动机状态并没有显着影响控制的记忆表现。这项研究表明，EC-SOD过表达的小鼠在桡臂迷宫中并不是不能学习和记忆，但在低动机状态下，允许对照动物很好地完成这项任务的机制在EC-SOD过表达的小鼠中是缺乏的。
Extracellular superoxide dismutase (EC-SOD) controls the availability of extracellular superoxide and appears to play a role in controlling intercellular signaling. In this role EC-SOD can have potent effects on neurobehavioral function. In previous studies, we have found that either over- or under-expression of EC-SOD in mice significantly impairs spatial learning on the radial-arm maze. In the current study, the neurobehavioral nature of the EC-SOD role in cognitive function was determined. EC-SOD overexpression altered the relationship between both learning and memory with motivational state. Mice were tested in the radial-arm maze under a high motivational state (22–24 hours of food restriction) or a low motivational state (4–6 hours of food restriction). Under a high motivational state, the EC-SOD overexpressing mice were able to learn in the radial-arm maze, albeit at a slightly lower rate than wild-type controls. This contrasts with the failure to learn by EC-SOD overexpressing mice in our previous study conducted with the low motivational state. The change in motivational state did not significantly alter the learning rate of controls. Similarly, during postacquisition memory phase of testing, the EC-SOD overexpressing mice were significantly worse than controls when tested in a low motivational state but not under a high motivation state. As with learning, motivational state did not significantly affect memory performance in controls. This study shows that mice with EC-SOD overexpression are not incapable of learning and memory in the radial-arm maze, but that the mechanisms which allow control animals to perform this task well under low motivational states are deficient in the mice with EC-SOD overexpression.