Individual Differences in the Expression of a “General” Learning Ability in Mice
Individual Differences in the Expression of a “General” Learning Ability in Mice
复制标题
小鼠“一般”学习能力表达的个体差异
作者：
L. Matzel;Y. Han;H. Grossman;Meghana Karnik;D. Patel;Nicholas W. Scott;S. M. Specht;C. Gandhi
人类在各种智力测试中的表现受到“一般”监管因素的影响，该因素在智力测试中导致个体之间的差异高达 50%。一般认知能力的神经生物学决定因素基本上是未知的，部分原因是缺乏可以进行神经生物学分析的动物研究。我们报告了一种评估实验室小鼠一般学习能力个体差异的方法。评估了小鼠的联想恐惧条件反射、操作性回避、路径整合、辨别和空间导航测试的能力。任务的设计使得每项任务对动物都有独特的感觉、运动、动机和信息处理要求。使用 56 只基因多样化的远交小鼠 (CD-1) 样本来评估个体对每项任务的掌握情况。个体在所有任务上的表现之间都存在正相关性，这表明了方差的共同来源。当对多个测试电池进行测试时，发现个体的整体性能排名高度可靠并且呈“正态”分布。对学习表现变量的因子分析确定，单个因素占动物总方差的 38%。尽管动物的探索倾向与学习能力密切相关（并且呈正相关），但动物的自然活动水平和体重对学习的变异性影响很小。这些结果表明，实验室小鼠的不同学习能力受到共同方差来源的影响，而且，个体小鼠的一般学习能力可以相对于同伴样本来指定。
Human performance on diverse tests of intellect are impacted by a “general” regulatory factor that accounts for up to 50% of the variance between individuals on intelligence tests. Neurobiological determinants of general cognitive abilities are essentially unknown, owing in part to the paucity of animal research wherein neurobiological analyses are possible. We report a methodology with which we have assessed individual differences in the general learning abilities of laboratory mice. Abilities of mice on tests of associative fear conditioning, operant avoidance, path integration, discrimination, and spatial navigation were assessed. Tasks were designed so that each made unique sensory, motor, motivational, and information processing demands on the animals. A sample of 56 genetically diverse outbred mice (CD-1) was used to assess individuals' acquisition on each task. Indicative of a common source of variance, positive correlations were found between individuals' performance on all tasks. When tested on multiple test batteries, the overall performance ranks of individuals were found to be highly reliable and were “normally” distributed. Factor analysis of learning performance variables determined that a single factor accounted for 38% of the total variance across animals. Animals' levels of native activity and body weights accounted for little of the variability in learning, although animals' propensity for exploration loaded strongly (and was positively correlated) with learning abilities. These results indicate that diverse learning abilities of laboratory mice are influenced by a common source of variance and, moreover, that the general learning abilities of individual mice can be specified relative to a sample of peers.