Department of Animals in Science and Society, Division of Animal Welfare and Laboratory Animal Science, Utrecht University, Utrecht, The Netherlands.
Behav Brain Res. 2012 Jul 15;233(1):45-54. doi: 10.1016/j.bbr.2012.04.039. Epub 2012 Apr 26.
Emotional states are known to affect cognitive processes. For example highly anxious individuals interpret ambiguous stimuli more negatively than low anxious people, an effect called negative judgement bias. Recently, the measurement of judgement bias has been used to try and indicate emotional states in animals. In the present experiment a potential test for judgement bias in mice was examined. Mice were trained with two distinct odour cues (vanilla or apple) predicting either a palatable or an unpalatable almond piece. Subsequently their reaction to mixtures of both odours, the ambiguous stimuli, was investigated. Mice of the BALB/cJ and 129P3/J inbred mouse strains (high initial anxiety and low initial anxiety phenotypes respectively) were tested. While BALB/cJ mice showed odour association learning and showed intermediate reactions to the ambiguous cues, 129P3/J mice did not discriminate between the cues. Additionally BALB/cJ mice that were tested under more aversive white light conditions revealed a higher latency to approach the almond piece than mice tested under less aversive red light conditions. The ambiguous stimulus however was interpreted as negative under both test conditions. Brain c-Fos expression levels (a marker for neuronal activity) differed between the BALB/c/J and 129P3/J in the lateral amygdala and the prelimbic cortex, indicating differences in ambiguous information processing between the strains. The behavioural results suggest that the present judgement bias test might be used to assess emotional states in at least BALB/c mice, however further research on both behaviour and on the involved brain mechanisms is necessary to confirm this idea.
情绪状态已知会影响认知过程。例如，高度焦虑的个体比低焦虑的个体对模棱两可的刺激有更负面的解释，这种效应称为负面判断偏差。最近，判断偏差的测量已被用于尝试指示动物的情绪状态。在本实验中，研究了一种用于检测小鼠判断偏差的潜在测试方法。用两种不同的气味线索（香草或苹果）训练小鼠，这些线索预测是美味的还是难吃的杏仁片。随后，研究了它们对两种气味混合物（模棱两可的刺激）的反应。测试了 BALB/cJ 和 129P3/J 近交系小鼠（分别具有较高和较低的初始焦虑表型）。虽然 BALB/cJ 小鼠表现出气味关联学习，对模棱两可的线索表现出中等反应，但 129P3/J 小鼠不能区分这些线索。此外，在更具厌恶的白光条件下测试的 BALB/cJ 小鼠比在较不厌恶的红光条件下测试的小鼠，接近杏仁片的潜伏期更长。然而，在这两种测试条件下，模棱两可的刺激都被解释为负面的。BALB/c/J 和 129P3/J 之间的外侧杏仁核和前额皮质中的脑 c-Fos 表达水平（神经元活动的标志物）不同，表明两种品系之间的模糊信息处理存在差异。行为结果表明，目前的判断偏差测试可能至少用于评估 BALB/c 小鼠的情绪状态，但是需要对行为和涉及的大脑机制进行进一步的研究，以确认这一观点。
