Spatial maps in piriform cortex during olfactory navigation

Odours are a fundamental part of the sensory environment used by animals to guide behaviours such as foraging and navigation(1,2). Primary olfactory (piriform) cortex is thought to be the main cortical region for encoding odour identity(3-8). Here, using neural ensemble recordings in freely moving rats performing an odour-cued spatial choice task, we show that posterior piriform cortex neurons carry a robust spatial representation of the environment. Piriform spatial representations have features of a learned cognitive map, being most prominent near odour ports, stable across behavioural contexts and independent of olfactory drive or reward availability. The accuracy of spatial information carried by individual piriform neurons was predicted by the strength of their functional coupling to the hippocampal theta rhythm. Ensembles of piriform neurons concurrently represented odour identity as well as spatial locations of animals, forming an odour-place map. Our results reveal a function for piriform cortex in spatial cognition and suggest that it is well-suited to form odour-place associations and guide olfactory-cued spatial navigation.

Automated summary

The study demonstrates that posterior piriform cortex neurons can carry a spatial representation of the environment, showing features of a learned cognitive map that is stable across behavioral contexts and independent of olfactory drive or reward availability. The accuracy of spatial information carried by individual piriform neurons is predicted by their functional coupling strength to the hippocampal theta rhythm, and ensembles of piriform neurons concurrently represent odor identity and spatial locations of animals.