Neural mechanisms for spatial cognition across vertebrates

The ability to navigate the world is a critical cognitive skill that most animals use to find food, shelter, and mates. Understanding the neural basis of navigation requires probing how the brain encodes spatial information through the study of the activity of single neurons and neuronal populations. Classically in vertebrates, studies have centered on the rodent hippocampal formation, which led to the discovery of place, grid, head direction and other cell types. However, since navigation skills are essential to almost all vertebrates, spatial cognition in different species also needs to be explored. In recent years, as a result of advances in technology, new data have emerged on the ways in which space is represented during navigation in the brains of vertebrates other than rodents, including teleost fish, birds, and other mammal species. Here, we review the state of the art on the neural representation of an animal’s position and motion across vertebrates at the level of single neurons. We argue that it is time to pool information across vertebrates to identify the underlying algorithms that lead to successful navigation. Although rodent-based data are important, findings in rodents are unlikely to cover the full spectrum of neural computations supporting navigation strategies in the vertebrate kingdom. Studying other species can shed light on length scales such as in large environments, and different scenarios such as naturalistic environments that are hard to carry out in rodents. In addition, a rodent-centric view may neglect the fact that different species are likely to represent positions in the world in ways that do not exist in mammals. Finally, we provide an outlook for the future which includes prediction about findings in unexplored species, and the opportunities for discoveries and understanding in this field.