Konrad Lorenz Institute for Evolution and Cognition Research, Adolf Lorenz Gasse 2, A-3422 Altenberg, Austria.
Behav Brain Res. 2012 Jun 15;232(1):7-12. doi: 10.1016/j.bbr.2012.03.014. Epub 2012 Mar 30.
Behavioural and brain left-right asymmetries are a common feature among the animal kingdom. Lateralization often manifests itself at the population-level with most individuals showing the same direction of lateral bias. Theoretical model based on evolutionary stable strategy predicts that lateralization at the population-level is more likely to characterize social rather than solitary species. Empirical data supporting this hypothesis has been recently obtained in Hymenoptera showing that eusocial honeybees present an asymmetrical use of the antennae: the right antenna is involved in olfactory learning and present more olfactory receptors. However, no evidences about the role of antennal asymmetries in social interactions have been provided so far. Highly social ant species belonging to Formica rufa group are a good model for investigating natural communication because they are able to pass exact information to their nest mates. We applied the "binary tree" experimental paradigm, which allowed us to observe different types of antennal contacts performed by ants out of their nest. To examine possible asymmetrical use of the right and left antenna, we focused on "feeding" (the simplest) contacts where a "donor" ant is exchanging food with a "receiver" ant through trophallaxis. We observed a population-level asymmetry, with the "receiver" ant using the right antenna significantly more often than the left antenna. This study provides the first evidence of lateralization in antennal contacts in ants, and seems to support the hypothesis of mathematical models on the evolution of lateralization suggesting that the alignment of lateralization at the population-level matters in social interactions.
行为和大脑左右不对称是动物王国的一个共同特征。偏侧性通常在群体水平上表现出来，大多数个体表现出相同的偏侧性方向。基于进化稳定策略的理论模型预测，群体水平上的偏侧性更可能是社会性而不是独居物种的特征。最近在膜翅目昆虫中获得的支持这一假设的实证数据表明，群居的蜜蜂表现出触角的不对称使用：右触角参与嗅觉学习，并且具有更多的嗅觉受体。然而，迄今为止，还没有提供关于触角不对称在社会互动中的作用的证据。属于红火蚁群的高度社会性蚂蚁物种是研究自然通讯的良好模型，因为它们能够将准确的信息传递给巢内的同伴。我们应用了“二叉树”实验范式，该范式允许我们观察蚂蚁在巢外进行的不同类型的触角接触。为了研究右触角和左触角可能存在的不对称使用，我们专注于“喂食”（最简单）接触，其中一只“供体”蚂蚁通过营养交换与一只“受体”蚂蚁交换食物。我们观察到了群体水平上的不对称性，“受体”蚂蚁使用右触角的频率明显高于左触角。这项研究提供了蚂蚁触角接触中偏侧性的第一个证据，似乎支持了关于偏侧性进化的数学模型的假设，即群体水平上的偏侧性对齐在社会互动中很重要。
