Editing Place cell (section)

=== Directionality ===
In some cases place cells show directionality, meaning they will only fire in a location when the subject is travelling in a particular direction. However, they may also be omnidirectional, meaning they fire regardless of the direction the subject. The lack of directionality in some place cells might occur particularly in impoverished environments, whereas in more complicated environments directionality is enhanced.<ref name="Muller-1994">{{Cite journal|last1=Muller|first1=R. U.|last2=Bostock|first2=E.|last3=Taube|first3=J. S.|last4=Kubie|first4=J. L.|date=1994|title=On the directional firing properties of hippocampal place cells|journal=Journal of Neuroscience|language=en|volume=14|issue=12|pages=7235–7251|doi=10.1523/JNEUROSCI.14-12-07235.1994|issn=0270-6474|pmid=7996172|pmc=6576887}}</ref> The [[radial arm maze]] is one such environment where directionality does occur. In this environment, cells may even have multiple place fields, of which one is strongly directional, while the others are not.<ref name="Muller-1994" /> In virtual reality corridors, the degree of directionality in the population of place cells is particularly high.<ref>{{Cite journal|last1=Dombeck|first1=Daniel A.|last2=Harvey|first2=Christopher D.|last3=Tian|first3=Lin|last4=Looger|first4=Loren L.|last5=Tank|first5=David W.|date=2010|title=Functional imaging of hippocampal place cells at cellular resolution during virtual navigation|journal=Nature Neuroscience|language=en|volume=13|issue=11|pages=1433–1440|doi=10.1038/nn.2648|pmid=20890294|pmc=2967725|issn=1546-1726}}</ref> The directionality of place cells has been shown to emerge as a result of the animal's behaviour. For example, the receptive fields become skewed when rats travel a linear track in a single direction.<ref>{{Cite journal|last1=Mehta|first1=Mayank R.|last2=Quirk|first2=Michael C.|last3=Wilson|first3=Matthew A.|date=March 2000|title=Experience-Dependent Asymmetric Shape of Hippocampal Receptive Fields|journal=Neuron|language=en|volume=25|issue=3|pages=707–715|doi=10.1016/S0896-6273(00)81072-7|pmid=10774737|doi-access=free}}</ref> Recent theoretical studies suggest that place cells encode a [[successor representation]] which maps the current state to the predicted successor states, and that directionality emerges from this formalism.<ref name="Stachenfeld-2017" /> This computational framework also provides an account for the distortion of place fields around obstacles.<ref>{{Cite journal|last1=Alvernhe|first1=Alice|last2=Save|first2=Etienne|last3=Poucet|first3=Bruno|date=May 2011|title=Local remapping of place cell firing in the Tolman detour task: Place cell firing and detour behavior|url=http://doi.wiley.com/10.1111/j.1460-9568.2011.07653.x|journal=European Journal of Neuroscience|language=en|volume=33|issue=9|pages=1696–1705|doi=10.1111/j.1460-9568.2011.07653.x|pmid=21395871|s2cid=41211033|url-access=subscription}}</ref>