Place Cells: Knowing Where You Are Depends on Knowing Where You’re Heading
This piece is on this cracking paper by Harland ea. (abstract at bottom):
Current Biology, Available online 31 August 2017
Knowing where you are and knowing where you are heading are both necessary for navigation. Does knowing where you are depend on knowing where you are heading, or is it the other way around? A new study suggests that knowing where you are heading allows you to know where you are.
Understanding how motile animals navigate in large-scale environments is a significant intellectual challenge, with implications extending across many domains from biologically-inspired mobile robots to human dementia patients suffering from disorders of orientation and spatial knowledge. Navigation by animals and humans was posed by Tolman  as a psychological and behavioural question — do we possess flexible cognitive maps of space that drive our behaviour? — a view directly counterposed to Hull’s theory  that we learn specific response sequences supporting navigation. The behavioural data favoured Tolman’s cognitive map theory, as did supporting theoretical analyses by Hebb  and Lashley …
References cited above:
1 E.C. Tolman Cognitive maps in rats and men Psychol. Rev., 55 (1948), pp. 189–208
2 C.L. Hull Principles of Behavior Appleton-Century-Crofts, New York (1943)
3 D.O. Hebb The Organization of Behavior Wiley and Sons, New York (1949)
4 K.S. Lashley The problem of serial order in behavior L.A. Jeffress (Ed.), Cerebral Mechanisms in Behavior: The Hixon Symposium, Wiley and Sons, New York (1951), pp. 112–136
Harland et al:
Place fields repeat across parallel maze compartments, but not radial compartments
Lateral mammillary nuclei lesions increase field repetition in radial compartments
Head direction cells may drive place fields
A central tenet of systems neuroscience is that the mammalian hippocampus provides a cognitive map of the environment. This view is supported by the finding of place cells, neurons whose firing is tuned to specific locations in an animal’s environment, within this brain region. Recent work, however, has shown that these cells repeat their firing fields across visually identical maze compartments [1, 2]. This repetition is not observed if these compartments face different directions, suggesting that place cells use a directional input to differentiate otherwise similar local environments [3, 4]. A clear candidate for this input is the head direction cell system. To test this, we disrupted the head direction cell system by lesioning the lateral mammillary nuclei and then recorded place cells as rats explored multiple, connected compartments, oriented in the same or in different directions. As shown previously, we found that place cells in control animals exhibited repeated fields in compartments arranged in parallel, but not in compartments facing different directions. In contrast, the place cells of animals with lesions of the head direction cell system exhibited repeating fields in both conditions. Thus, directional information provided by the head direction cell system appears essential for the angular disambiguation by place cells of visually identical compartments.