Spatially Periodic Activation Patterns of Retrosplenial Cortex Encode Route Sub-spaces and Distance Traveled

Curr Biol. 2017 Jun 5;27(11):1551-1560.e4. doi: 10.1016/j.cub.2017.04.036. Epub 2017 May 18.


Traversal of a complicated route is often facilitated by considering it as a set of related sub-spaces. Such compartmentalization processes could occur within retrosplenial cortex, a structure whose neurons simultaneously encode position within routes and other spatial coordinate systems. Here, retrosplenial cortex neurons were recorded as rats traversed a track having recurrent structure at multiple scales. Consistent with a major role in compartmentalization of complex routes, individual retrosplenial cortex (RSC) neurons exhibited periodic activation patterns that repeated across route segments having the same shape. Concurrently, a larger population of RSC neurons exhibited single-cycle periodicity over the full route, effectively defining a framework for encoding of sub-route positions relative to the whole. The same population simultaneously provides a novel metric for distance from each route position to all others. Together, the findings implicate retrosplenial cortex in the extraction of path sub-spaces, the encoding of their spatial relationships to each other, and path integration.

Keywords: distance; fragmentation; hippocampus; path integration; periodicity; retrosplenial cortex; spatial navigation; spatial representation; sub-route; sub-space.

MeSH terms

  • Animals
  • Brain Mapping
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiopathology*
  • Hippocampus / cytology
  • Hippocampus / physiology
  • Male
  • Maze Learning
  • Memory / physiology*
  • Models, Animal
  • Models, Biological
  • Neurons / physiology*
  • Rats
  • Rats, Long-Evans
  • Space Perception / physiology*