School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK.
School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, UK.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2023 Jul;209(4):737-746. doi: 10.1007/s00359-023-01613-1. Epub 2023 Feb 15.
Wood ants are excellent navigators, using a combination of innate and learnt navigational strategies to travel between their nest and feeding sites. Visual navigation in ants has been studied extensively, however, we have little direct evidence for the underlying neural mechanisms. Here, we perform lateralized mechanical lesions in the central complex (CX) of wood ants, a midline structure known to allow an insect to keep track of the direction of sensory cues relative to its own orientation and to control movement. We lesioned two groups of ants and observed their behaviour in an arena with a large visual landmark present. The first group of ants were naïve and when intact such ants show a clear innate attraction to the conspicuous landmark. The second group of ants were trained to aim to a food location to the side of the landmark. The general heading of naïve ants towards a visual cue was not altered by the lesions, but the heading of ants trained to a landmark adjacent food position was affected. Thus, CX lesions had a specific impact on learnt visual guidance. We also observed that lateralised lesions altered the fine details of turning with lesioned ants spending less time turning to the side ipsilateral of the lesion. The results confirm the role of the CX in turn control and highlight its important role in the implementation of learnt behaviours that rely on information from other brain regions.
木蚁是出色的导航者，它们将先天的和后天习得的导航策略相结合，在蚁巢和觅食地之间往返。蚂蚁的视觉导航已经得到了广泛的研究，但我们对其潜在的神经机制知之甚少。在这里，我们对木蚁的中央复合体（CX）进行了单侧机械损伤，这是一种中线结构，已知它可以使昆虫跟踪相对于自身方向的感觉线索的方向，并控制运动。我们对两组蚂蚁进行了损伤，并在一个有明显视觉标记的竞技场中观察它们的行为。第一组蚂蚁是未受过训练的，当它们完好无损时，会表现出对明显标记的先天吸引力。第二组蚂蚁接受了训练，以目标为导向，向位于标记物旁边的食物位置移动。未受过训练的蚂蚁对视觉线索的大致朝向没有因损伤而改变，但受过训练的蚂蚁对标记物附近食物位置的朝向则受到影响。因此，CX 损伤对后天视觉引导有特定影响。我们还观察到，单侧损伤改变了转向的细节，损伤蚂蚁花在向损伤侧转弯的时间更少。研究结果证实了 CX 在转向控制中的作用，并强调了它在执行依赖于其他大脑区域信息的后天行为中的重要作用。
