Arabo Arnaud, Potier Claire, Ollivier Gaëlle, Lorivel Thomas, Roy Vincent
Laboratoire de Psychologie et Neurosciences de la Cognition et de l'Affectivité, Université de Rouen.
J Exp Psychol Anim Learn Cogn. 2014 Oct;40(4):457-66. doi: 10.1037/xan0000031. Epub 2014 Jun 9.
The elevated plus-maze (EPM) is a very common rodent test of anxiety. It is based on an approach-avoidance conflict between secure closed arms and aversive open arms. However, discrepancies remain on the interpretation of animals' behavior in this assay. The purpose of our study was to get a better understanding of the mouse behavior in the EPM. We applied a minute-by-minute analysis to compare the behavior of mice forcibly exposed to the maze or set free to explore the maze from a familiar box. Three strains of mice (CD1, BALB/c, and C57Bl/6) were tested. The combination of our different conditions of the test with the minute-by-minute analysis showed that mice did not avoid open arms during the first 2 min of the test when they were forcibly exposed to the EPM. Conversely, free exploration of the EPM resulted in a pattern of behavior characterized by open arm avoidance from the outset, demonstrating that open arm avoidance in mice is unconditioned. These findings generalize across the 3 mouse strains. These data suggest that rodents enter the open arms to complete spatial information about the apparatus as a whole before their natural tendency to avoid them is expressed. Our data also indicate that a detailed behavioral analysis is needed whenever BALB/c mice are to be exposed by force to the EPM. Further studies are required to fully understand the behavior of rodents in the EPM and to avoid false interpretations in the fields of psychopharmacology and behavioral neuroscience.
高架十字迷宫（EPM）是一种非常常见的用于啮齿动物的焦虑测试。它基于安全的封闭臂与厌恶的开放臂之间的趋避冲突。然而，对于该实验中动物行为的解释仍存在差异。我们研究的目的是更好地理解小鼠在高架十字迷宫中的行为。我们采用逐分钟分析来比较被强行置于迷宫中的小鼠或从熟悉的盒子中被释放自由探索迷宫的小鼠的行为。测试了三种品系的小鼠（CD1、BALB/c和C57Bl/6）。我们不同测试条件与逐分钟分析的结合表明，当被强行置于高架十字迷宫中时，小鼠在测试的前2分钟内不会避开开放臂。相反，自由探索高架十字迷宫会导致一种从一开始就以避开开放臂为特征的行为模式，这表明小鼠对开放臂的回避是无条件的。这些发现适用于这三种小鼠品系。这些数据表明，啮齿动物在其自然避开开放臂的倾向表现出来之前，会进入开放臂以获取关于整个实验装置的空间信息。我们的数据还表明，每当要将BALB/c小鼠强行置于高架十字迷宫中时，都需要进行详细的行为分析。需要进一步研究以充分理解啮齿动物在高架十字迷宫中的行为，并避免在精神药理学和行为神经科学领域出现错误的解释。
