The assessment of pain using facial expressions in laboratory mice, rats, rabbits and macaques.

在世界范围内，数以百万计的实验动物作为重要科学研究的一部分，经历着可能会带来痛苦的过程。为了减轻这种痛苦，我们必须能够有效地认识到它并评估其严重性。尽管我们在有效评估动物疼痛方面取得了相当大的进展，但目前的方法仍存在迫切需要克服的主要局限性：(1)由于开发和应用这些方法非常耗时，因此在少数实验动物物种的非常有限的疼痛过程中已经确定了有效的疼痛指标；(2)目前的方法只能测量一种动物？对疼痛的生理反应，而不是疼痛带给他们的感觉。对人类来说，我们对疼痛的感受比我们对疼痛的身体反应更重要；(3)一些常规使用的止痛药（如吗啡类药物）会引起常用疼痛指标的变化，这些变化与疼痛反应相似；(4)当我们试图评估动物的疼痛时，我们似乎把注意力集中在动物的脸上，但几乎所有目前使用的疼痛指标都没有在脸上观察到。对疼痛反应的面部表情的评估可能为这些限制提供了一个解决方案。面部表情通常用于评估人类的疼痛和其他情绪状态，特别是那些无法言语交流的人（例如新生儿）。我们将研究面部表情是否可以有效地用于测量动物在潜在疼痛手术后的疼痛，以及这种方法是否是对当前技术的改进。我们将开发和应用几种不同物种的面部表情测量。我们将使用它和现有的方法，来评估不同手术后疼痛的持续时间和严重程度。我们还将测试面部表情是否可以用来评估减轻疼痛的方法的有效性（例如止痛药的施用），并开发和应用更人性化的终点。首先，我们将评估小鼠的面部表情是否会在急性（如手术后）和慢性（如癌症）疼痛相关的手术后发生变化。然后，我们将评估是否可以使用类似的方法来评估大鼠、兔子和猕猴的术后疼痛。值得注意的是，我们目前还没有客观的方法来评估非人灵长类动物的术后疼痛。

Worldwide millions of laboratory animals undergo potentially painful procedures as part of essential scientific research. In order for this pain to be relieved we must be able to effectively recognise it and to assess its severity. Although we have made considerable advances in the effective assessment of animal pain our current methods have major limitations that urgently need to be overcome: (1) Effective indicators of pain have been identified for a very limited range of painful procedures in a small number of laboratory animal species, because developing and applying the methods are very time consuming; (2) Current methods may only measure an animals? physical reaction to pain rather than how it makes them ?feel?. In humans, how we feel about our pain is more important than our physical reaction to it; (3) Some routinely used painkillers (e.g. morphine-like drugs) cause changes in commonly used indicators of pain that are similar to those seen in response to pain; (4) We seem to focus on the face of animals when trying to assess their pain, but almost all of the currently used indicators of pain are not observed in the face. The assessment of facial expressions exhibited in response to pain may offer a solution to these limitations. Facial expressions are often used in assessments of pain and other emotional states in humans, particularly in those who are unable to communicate verbally (e.g. newborn babies). We will investigate whether facial expressions can effectively be used to measure pain in animals following potentially painful procedures and whether this approach is an improvement on current techniques. We will develop and apply measurement of facial expressions in several different species. We will use it, together with existing methods, to assess the duration and severity of pain after different procedures. We will also test whether facial expressions can be use to evaluate the effectiveness of methods to alleviate pain (e.g. painkiller administration) and to develop and apply more humane endpoints.Initially we will assess whether facial expressions in mice change following procedures associated with both acute (e.g. post-surgical) and chronic (e.g. cancer) pain. We will then assess whether a similar approach can be used to assess post-surgical pain in rats, rabbits and macaques. It is important to note that we currently have no objective method of assessing post-operative pain in non-human primates.