Department of Psychology, Occidental College, Los Angeles, California, United States of America.
PLoS One. 2012;7(10):e46606. doi: 10.1371/journal.pone.0046606. Epub 2012 Oct 3.
For social omnivores such as rats and humans, taste is far more than a chemical sense activated by food. By virtue of evolutionary and epigenetic elaboration, taste is associated with negative affect, stress vulnerability, responses to psychoactive substances, pain, and social judgment. A crucial gap in this literature, which spans behavior genetics, affective and social neuroscience, and embodied cognition, concerns links between taste and social behavior in rats. Here we show that rats selectively bred for low saccharin intake are subordinate to high-saccharin-consuming rats when they compete in weight-matched dyads for food, a task used to model depression. Statistical and experimental controls suggest that differential resource utilization within dyads is not an artifact of individual-level processes such as apparatus habituation or ingestive motivation. Tail skin temperature measurements showed that LoS rats display larger hyperthermic responses to social interaction after status is established, evidence linking taste, social stress, autonomic reactivity, and depression-like symptoms. Based on regression using early- and late-competition predictors to predict dyadic disparity in final competition scores, we tentatively suggest that HiS rats emerge as dominant both because of an "early surge" on their part and because LoS acquiesce later. These findings should invigorate the comparative study of individual differences in social status and its relationship to mental and physical health.
对于像老鼠和人类这样的社会杂食动物来说，味觉远不止是一种由食物激活的化学感觉。由于进化和表观遗传的精心设计，味觉与负面情绪、压力易感性、对精神活性物质的反应、疼痛和社会判断有关。在跨越行为遗传学、情感和社会神经科学以及具身认知的文献中，存在一个关键的空白，即涉及老鼠味觉和社会行为之间的联系。在这里，我们表明，在蔗糖摄入量较低的大鼠中进行选择性繁殖，当它们在体重匹配的双体中竞争食物时，处于从属地位，而这种任务用于模拟抑郁。统计和实验控制表明，双体中资源利用的差异不是个体水平过程（例如仪器习惯或摄取动机）的人为产物。尾部皮肤温度测量显示，LoS 大鼠在建立地位后对社交互动的反应更大，这将味觉、社会压力、自主反应和类似抑郁的症状联系起来。基于使用早期和晚期竞争预测因子来预测最终竞争得分中双体差异的回归，我们初步认为，HiS 大鼠之所以表现出优势，既是因为它们自身的“早期激增”，也是因为 LoS 后来的默认。这些发现应该激发对社会地位的个体差异及其与身心健康关系的比较研究。
