Department of Biology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford, Oxfordshire OX1 3SZ, UK.
Proc Biol Sci. 2022 Oct 12;289(1984):20221220. doi: 10.1098/rspb.2022.1220.
Neurophysiological advances have given us exciting insights into the systems responsible for spatial mapping in mammals. However, we are still lacking information on the evolution of these systems and whether the underlying mechanisms identified are universal across phyla, or specific to the species studied. Here we address these questions by exploring whether a species that is evolutionarily distant from mammals can perform a task central to mammalian spatial mapping-distance estimation. We developed a behavioural paradigm allowing us to test whether goldfish () can estimate distance and explored the behavioural mechanisms that underpin this ability. Fish were trained to swim a set distance within a narrow tank covered with a striped pattern. After changing the background pattern, we found that goldfish use the spatial frequency of their visual environment to estimate distance, doubling the spatial frequency of the background pattern resulted in a large overestimation of the swimming distance. We present robust evidence that goldfish can accurately estimate distance and show that they use local optic flow to do so. These results provide a compelling basis to use goldfish as a model system to interrogate the evolution of the mechanisms that underpin spatial cognition, from brain to behaviour.
神经生理学的进展让我们对负责哺乳动物空间映射的系统有了令人兴奋的了解。然而，我们仍然缺乏关于这些系统的进化的信息，也不知道所确定的潜在机制是否在所有门中是普遍存在的，还是仅存在于所研究的物种中。在这里，我们通过探索一种与哺乳动物在进化上相距甚远的物种是否能够执行一个对哺乳动物空间映射距离估计至关重要的任务来解决这些问题。我们开发了一种行为范式，使我们能够测试金鱼是否可以估计距离，并探索了支持这种能力的行为机制。我们训练金鱼在一个覆盖有条纹图案的狭窄水箱内游一段固定的距离。在改变背景图案后，我们发现金鱼使用其视觉环境的空间频率来估计距离，将背景图案的空间频率增加一倍会导致对游泳距离的大幅高估。我们提供了确凿的证据表明金鱼可以准确地估计距离，并表明它们使用局部光流来做到这一点。这些结果为使用金鱼作为模型系统来探究从大脑到行为的空间认知机制的进化提供了强有力的依据。
