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Place field repetition and purely local remapping in a multicompartment environment.

Spiers HJ, Hayman RM, Jovalekic A, Marozzi E, Jeffery KJ - Cereb. Cortex (2013)

Bottom Line: Some studies report that place cells can disambiguate different compartments, while others report that they do not.Second, this repetition does not diminish with extended experience.Third, remapping was found to be purely local for both geometric change and contextual change.

View Article: PubMed Central - PubMed

Affiliation: Department of Cognitive, Perceptual and Brain Sciences, Division of Psychology and Language Sciences, Institute of Behavioural Neuroscience, University College London, UK.

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(A–C) Schematic of the apparatus in its 3 configurations: (A) The standard configuration showing 4 main identical compartments, connected by a long corridor. (B) The context remapping manipulation, in which 1 of the 2 middle compartments was changed from white to black by adding wall and floor inserts. (C) The wall-removal manipulation in which all of the interior walls except those surrounding the end compartment were removed. (D–E) Possible outcomes predicted on a plan view of the apparatus. Filled circles represent place fields from a single hypothetical place cell. (D) Spatial discrimination: If place cells are able to discriminate the compartments cells should produce unique firing patterns in the environment. In this example, a single field is shown, but other examples could include fields in each of the compartments, each occupying a different location. (E) No discrimination—place fields repeat across compartments, firing in the same location in each compartment. (F) Rate discrimination—place field locations repeat across compartments, but the peak rate is modulated across compartments. In this example, the highest peak rate (darkest circle) is in the first compartment, but the peak might occur in any of the compartments.
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BHT198F1: (A–C) Schematic of the apparatus in its 3 configurations: (A) The standard configuration showing 4 main identical compartments, connected by a long corridor. (B) The context remapping manipulation, in which 1 of the 2 middle compartments was changed from white to black by adding wall and floor inserts. (C) The wall-removal manipulation in which all of the interior walls except those surrounding the end compartment were removed. (D–E) Possible outcomes predicted on a plan view of the apparatus. Filled circles represent place fields from a single hypothetical place cell. (D) Spatial discrimination: If place cells are able to discriminate the compartments cells should produce unique firing patterns in the environment. In this example, a single field is shown, but other examples could include fields in each of the compartments, each occupying a different location. (E) No discrimination—place fields repeat across compartments, firing in the same location in each compartment. (F) Rate discrimination—place field locations repeat across compartments, but the peak rate is modulated across compartments. In this example, the highest peak rate (darkest circle) is in the first compartment, but the peak might occur in any of the compartments.

Mentions: Accordingly, we revisited the repeating-compartment experiment with place cells, using an environment with 4 compartments, instead of only 2, in which rats would forage rather than run ballistically (Fig. 1A). We expected that if the path integration informs place cells of compartment identity, the place fields should discriminate between compartments (Fig. 1D). Conversely, if the path integrator “resets” anew in every compartment, then place fields should have the same location in each compartment (Fig. 1E). In some experiments place cells have been found to discriminate different contexts by differences in their firing rate (rate coding), while maintaining their field location (Hayman et al. 2003; Leutgeb et al. 2005). Thus, place cells might be predicted to express a rate-based discrimination across compartments (Fig. 1F). As we show, place cells repeated their firing locations across these 4 compartments, even after extensive experience, and demonstrated some degree of rate-based discrimination. In addition, there was a prominent clustering of activity around the doorways of the compartments, suggesting that doorways are a particularly salient environmental feature. We then tested whether firing patterns provide a global or local code of the environment by examining whether changes to parts of the environment altered firing in connected but more distant regions. Purely local firing alterations were observed. Thus, in a free foraging situation, the location of place fields appears to be determined not by path integration but by purely local factors. We suggest that this may be due to resetting of the grid fields as the animals pass through doorways.Figure 1.


Place field repetition and purely local remapping in a multicompartment environment.

Spiers HJ, Hayman RM, Jovalekic A, Marozzi E, Jeffery KJ - Cereb. Cortex (2013)

(A–C) Schematic of the apparatus in its 3 configurations: (A) The standard configuration showing 4 main identical compartments, connected by a long corridor. (B) The context remapping manipulation, in which 1 of the 2 middle compartments was changed from white to black by adding wall and floor inserts. (C) The wall-removal manipulation in which all of the interior walls except those surrounding the end compartment were removed. (D–E) Possible outcomes predicted on a plan view of the apparatus. Filled circles represent place fields from a single hypothetical place cell. (D) Spatial discrimination: If place cells are able to discriminate the compartments cells should produce unique firing patterns in the environment. In this example, a single field is shown, but other examples could include fields in each of the compartments, each occupying a different location. (E) No discrimination—place fields repeat across compartments, firing in the same location in each compartment. (F) Rate discrimination—place field locations repeat across compartments, but the peak rate is modulated across compartments. In this example, the highest peak rate (darkest circle) is in the first compartment, but the peak might occur in any of the compartments.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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BHT198F1: (A–C) Schematic of the apparatus in its 3 configurations: (A) The standard configuration showing 4 main identical compartments, connected by a long corridor. (B) The context remapping manipulation, in which 1 of the 2 middle compartments was changed from white to black by adding wall and floor inserts. (C) The wall-removal manipulation in which all of the interior walls except those surrounding the end compartment were removed. (D–E) Possible outcomes predicted on a plan view of the apparatus. Filled circles represent place fields from a single hypothetical place cell. (D) Spatial discrimination: If place cells are able to discriminate the compartments cells should produce unique firing patterns in the environment. In this example, a single field is shown, but other examples could include fields in each of the compartments, each occupying a different location. (E) No discrimination—place fields repeat across compartments, firing in the same location in each compartment. (F) Rate discrimination—place field locations repeat across compartments, but the peak rate is modulated across compartments. In this example, the highest peak rate (darkest circle) is in the first compartment, but the peak might occur in any of the compartments.
Mentions: Accordingly, we revisited the repeating-compartment experiment with place cells, using an environment with 4 compartments, instead of only 2, in which rats would forage rather than run ballistically (Fig. 1A). We expected that if the path integration informs place cells of compartment identity, the place fields should discriminate between compartments (Fig. 1D). Conversely, if the path integrator “resets” anew in every compartment, then place fields should have the same location in each compartment (Fig. 1E). In some experiments place cells have been found to discriminate different contexts by differences in their firing rate (rate coding), while maintaining their field location (Hayman et al. 2003; Leutgeb et al. 2005). Thus, place cells might be predicted to express a rate-based discrimination across compartments (Fig. 1F). As we show, place cells repeated their firing locations across these 4 compartments, even after extensive experience, and demonstrated some degree of rate-based discrimination. In addition, there was a prominent clustering of activity around the doorways of the compartments, suggesting that doorways are a particularly salient environmental feature. We then tested whether firing patterns provide a global or local code of the environment by examining whether changes to parts of the environment altered firing in connected but more distant regions. Purely local firing alterations were observed. Thus, in a free foraging situation, the location of place fields appears to be determined not by path integration but by purely local factors. We suggest that this may be due to resetting of the grid fields as the animals pass through doorways.Figure 1.

Bottom Line: Some studies report that place cells can disambiguate different compartments, while others report that they do not.Second, this repetition does not diminish with extended experience.Third, remapping was found to be purely local for both geometric change and contextual change.

View Article: PubMed Central - PubMed

Affiliation: Department of Cognitive, Perceptual and Brain Sciences, Division of Psychology and Language Sciences, Institute of Behavioural Neuroscience, University College London, UK.

Show MeSH
Related in: MedlinePlus