Abstract:
The behavioral, sensory, and neural bases of vertebrate navigation are primarily described in mammals and birds. However, we know much less about navigational abilities and mechanisms of vertebrates that move on smaller scales, such as amphibians. To address this knowledge gap, we conducted an extensive field study on navigation in the cane toad, Rhinella marina. First, we performed a translocation experiment to describe how invasive toads in Hawai\'i navigate home following displacements of up to one kilometer. Next, we tested the effect of olfactory and magnetosensory manipulations on homing, as these senses are most commonly associated with amphibian navigation. We found that neither ablation alone prevents homing, suggesting that toad navigation is multimodal. Finally, we tested the hypothesis that the medial pallium, the amphibian homolog to the hippocampus, is involved in homing. By comparing neural activity across homing and non-homing toads, we found evidence supporting the involvement of the medial pallium, lateral pallium, and septum in navigation, suggesting a conservation of neural structures supporting navigation across vertebrates. Our study lays the foundation to understand the behavioral, sensory, and neural bases of navigation in amphibians and to further characterize the evolution of behavior and neural structures in vertebrates.
摘要:
行为,感官,脊椎动物导航的神经基础主要在哺乳动物和鸟类中描述。然而,我们对在较小尺度上移动的脊椎动物的导航能力和机制知之甚少,比如两栖动物。为了解决这个知识差距,我们对甘蔗蟾蜍的导航进行了广泛的实地研究,莱茵娜码头.首先,我们进行了一项易位实验,以描述夏威夷的入侵蟾蜍如何在长达一公里的位移后导航回家。接下来,我们测试了嗅觉和磁感操作对归巢的影响,因为这些感官通常与两栖动物导航有关。我们发现,单独的消融都不能阻止归巢,这表明蟾蜍导航是多模式的。最后,我们检验了这样一个假设,即内侧皮层,海马的两栖动物同源物,参与归巢。通过比较归巢和非归巢蟾蜍的神经活动,我们发现了支持内侧大脑皮层受累的证据,侧皮层,和导航中的隔膜,表明神经结构的保守性支持跨脊椎动物的导航。我们的研究为理解行为奠定了基础,感官,和两栖动物导航的神经基础,并进一步表征脊椎动物行为和神经结构的演变。