Schulz Daniela, Huston Joseph P, Buddenberg Tim, Topic Bianca
Institute of Physiological Psychology and Center for Biological and Medical Research, University of Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
Neurobiol Learn Mem. 2007 Mar;87(3):309-23. doi: 10.1016/j.nlm.2006.09.006. Epub 2006 Oct 31.
We have previously reported that extinction of escape behavior in the water maze due to the removal of the platform coincided with the development of behavioral "despair" in aged and adult rats, as assessed by immobility. The present study examines further predictions derived from the hypothesis that the withholding of reinforcement induces behaviors akin to depression. We tested for correlations between extinction performance and immobility, as well as between immobility and measures of anxiety in aged and adult rats. Age comparisons were also performed on these variables. Forty aged and 29 adult male Wistar rats (24 and 3 months old, respectively) were examined in the open field, black/white box and elevated-plus maze followed by 6 days of training in the water maze hidden platform task and 8 days of extinction without the platform. Indices of immobility increased over trials of extinction, with the aged showing higher levels, earlier onsets and larger slope increases of immobility than the adults. A lower resistance-to-extinction was predictive of more "despair" in both age groups. Between-group differences in the open field, black/white box and elevated-plus maze indicated that the aged showed more anxiety-like behavior than the adults and/or explored these environments less. Within the aged group, indicators of fearfulness in the three tests were predictive of higher levels of "despair". The extinction-despair model is held to provide the promise of a conceptual and empirical model of human depression that is the consequence of withdrawal of reinforcement.
我们之前曾报道，由于移除平台导致水迷宫中逃避行为的消退，与老年和成年大鼠行为“绝望”的发展同时发生，这是通过不动时间来评估的。本研究进一步检验了基于强化物剥夺会诱发类似抑郁行为这一假设得出的预测。我们测试了老年和成年大鼠的消退表现与不动时间之间的相关性，以及不动时间与焦虑测量指标之间的相关性。还对这些变量进行了年龄比较。40只老年雄性Wistar大鼠和29只成年雄性Wistar大鼠（分别为24个月龄和3个月龄）在旷场、黑白箱和高架十字迷宫中接受检查，随后在水迷宫隐藏平台任务中进行6天训练，然后在无平台的情况下进行8天消退实验。在消退实验过程中，不动指标随着实验次数增加而升高，老年大鼠的不动水平更高、开始时间更早且斜率增加幅度更大。在两个年龄组中，较低的消退抵抗能力预示着更多的“绝望”。在旷场、黑白箱和高架十字迷宫中的组间差异表明，老年大鼠比成年大鼠表现出更多类似焦虑的行为，并且/或者对这些环境的探索更少。在老年组内，这三项测试中的恐惧指标预示着更高水平的“绝望”。消退 - 绝望模型有望为人类抑郁提供一个概念性和实证性模型，该模型认为抑郁是强化物剥夺的结果。
