Most chronic stress protocols are too laborious or do not abide by the two main characteristics of the stress concept: uncontrollability and unpredictability. The goal of this study was to establish a simple and reliable model of chronic stress, while maintaining the main features of the concept. Animals were exposed to chronic movement restraint with variable duration (2, 4 or 6 h, in an unpredictable schedule) for 3 weeks and assessed in several physiological and behavioral readouts known to reflect chronic stress states. Body weight, levels of plasma corticosterone, hippocampal pro-and anti-inflammatory cytokines, anxiety-like (novelty suppressed feeding and elevated plus maze) and motivated behaviors (sucrose negative contrast test and forced swim test) were evaluated three days after the end of the chronic protocol. Stressed animals had a lower body weight gain, higher levels of cytokines in the hippocampus, reduced suppression of a low concentration sucrose solution and increased immobility in the forced swim test. Based on these data, we suggest that chronic movement restraint with variable duration may be a suitable and simple protocol for the study of changes induced by chronic stress and for the testing of possible treatments relevant to psychiatry.

大多数慢性压力协议过于费力或不遵守压力概念的两个主要特征：不可控制性和不可预测性。这项研究的目的是建立一个简单而可靠的慢性应激模型，同时保持这一概念的主要特征。使动物以可变的持续时间（2、4或6小时，以不可预测的时间表）暴露于慢性运动约束下3周，并通过已知反映慢性应激状态的几种生理和行为读数进行评估。在结束三天后评估体重，血浆皮质激素水平，海马促炎和消炎细胞因子，焦虑样症状（新颖性抑制进食和高迷宫度）和动机行为（蔗糖阴性对比试验和强迫游泳试验）。慢性方案。应激动物的体重增加较低，海马中的细胞因子水平较高，低浓度蔗糖溶液的抑制作用降低，强迫游泳试验中的固定性增加。基于这些数据，我们建议，可变持续时间的慢性运动约束可能是研究慢性应激诱发的变化和测试与精神病学有关的可能疗法的合适而简单的方案。