Department of Psychology, Tulane University, New Orleans, LA 70118, United States.
Behav Brain Res. 2011 Jan 20;216(2):525-30. doi: 10.1016/j.bbr.2010.08.028. Epub 2010 Aug 27.
Rodents learn to navigate mazes using various strategies that are governed by specific regions of the brain. The type of strategy used when learning to navigate a spatial environment is moderated by a number of factors including emotional states. Heightened anxiety states, induced by exposure to stressors or administration of anxiogenic agents, have been found to bias male rats toward the use of a striatum-based stimulus-response strategy rather than a hippocampus-based place strategy. However, no study has yet examined the relationship between natural anxiety levels, or trait anxiety, and the type of learning strategy used by rats on a dual-solution task. In the current experiment, levels of inherent anxiety were measured in an open field and compared to performance on two separate cognitive tasks, a Y-maze task that assessed place recognition memory, and a visible platform water maze task that assessed learning strategy. Results indicated that place recognition memory on the Y-maze correlated with the use of place learning strategy on the water maze. Furthermore, lower levels of trait anxiety correlated positively with better place recognition memory and with the preferred use of place learning strategy. Therefore, competency in place memory and bias in place strategy are linked to the levels of inherent anxiety in male rats.
啮齿动物通过大脑特定区域控制的各种策略来学习在迷宫中导航。在学习导航空间环境时使用的策略类型受到许多因素的调节,包括情绪状态。暴露于应激源或给予焦虑诱导剂会引起焦虑状态升高,这会使雄性大鼠偏向于使用基于纹状体的刺激-反应策略,而不是基于海马体的位置策略。然而,目前还没有研究检查自然焦虑水平或特质焦虑与大鼠在双解决方案任务中使用的学习策略类型之间的关系。在当前的实验中,在开阔场中测量了内在焦虑水平,并将其与两个单独的认知任务的表现进行了比较,一个是评估位置识别记忆的 Y 迷宫任务,另一个是评估学习策略的可见平台水迷宫任务。结果表明,Y 迷宫上的位置识别记忆与水迷宫上的位置学习策略的使用相关。此外,较低的特质焦虑水平与更好的位置识别记忆和更喜欢使用位置学习策略呈正相关。因此,雄性大鼠的固有焦虑水平与位置记忆能力和位置策略偏向有关。