Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada; Golestan University of Medical Sciences, Faculty of Nursing & Midwifery, Gorgan, Islamic Republic of Iran.
Department of Anatomy, Biology and Molecular Research Center, Babol University of Medical Sciences, Babol, Islamic Republic of Iran.
Horm Behav. 2014 Jan;65(1):66-75. doi: 10.1016/j.yhbeh.2013.11.007. Epub 2013 Dec 5.
Stress affects psychomotor profiles and exploratory behavior in response to environmental features. Here we investigated psychomotor and exploratory patterns induced by stress in a simple open-field arena and a complex, multi-featured environment. Groups of rats underwent seven days of restraint stress or no-stress conditions and were individually tested in three versions of the ziggurat task (ZT) that varied according to environmental complexity. The hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis due to stress procedure was evaluated by the pre- and post-stress levels of circulating corticosterone (CORT). Horizontal activity, exploration, and motivation were measured by the number of fields entered, the time spent in the central fields, path length and speed, and stop duration. In addition, vertical exploratory behavior was measured by the times rats climbed onto ziggurats. Stress-induced psychomotor changes were indicated by reduced path length and path speed and increased duration of stops only within the complex arena of the ZT. Rats in stress groups also showed a significant decline in the vertical movements as measured by the number of climbing onto ziggurats. No stress-induced changes were revealed by the simple open-field arena. The exploratory patterns of stressed animals suggest psychomotor inhibition and reduced novelty-seeking behaviors in an environment-dependent manner. Thus, multi-featured arenas that require complex behavioral strategies are ideally suited to reveal the inhibitory effects of stress on psychomotor capabilities in rodents.
压力会影响对环境特征做出反应的精神运动行为和探索行为。在这里，我们研究了在简单的开阔场和复杂的多特征环境中，压力引起的精神运动和探索模式。将几组大鼠进行七天的束缚应激或无应激处理，并在三种不同复杂程度的梯形塔任务（ZT）中进行个体测试。应激程序引起的下丘脑-垂体-肾上腺（HPA）轴的过度活跃通过循环皮质酮（CORT）的应激前后水平来评估。通过进入的场数、中央场的停留时间、路径长度和速度以及停留时间来测量水平活动、探索和动机。此外，通过大鼠爬上梯形塔的次数来测量垂直探索行为。仅在 ZT 的复杂场中，应激诱导的精神运动变化表现为路径长度和速度降低以及停留时间延长。应激组的大鼠在垂直运动方面的攀爬次数也明显减少。简单的开阔场没有显示出应激诱导的变化。应激动物的探索模式表明，在环境依赖性的情况下，精神运动受到抑制，对新奇事物的寻求行为减少。因此，需要复杂行为策略的多特征场地非常适合揭示应激对啮齿动物精神运动能力的抑制作用。
