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The firing pattern of entorhinal 'grid cells' is thought to provide an intrinsic metric for space. We report a strong experience-dependent environmental influence: the spatial scales of the grids (which are aligned and have fixed relative sizes within each animal) vary parametrically with changes to a familiar environment's size and shape. Thus grid scale(More)
We review evidence for the boundary vector cell model of the environmental determinants of the firing of hippocampal place cells. Preliminary experimental results are presented concerning the effects of addition or removal of environmental boundaries on place cell firing and evidence that boundary vector cells may exist in the subiculum. We review and(More)
We examined simultaneously recorded spikes from multiple rat grid cells, to explain mechanisms underlying their activity. Among grid cells with similar spatial periods, the population activity was confined to lie close to a two-dimensional (2D) manifold: grid cells differed only along two dimensions of their responses and otherwise were nearly identical.(More)
The spatially localized firing of rodent hippocampal place cells is strongly determined by the local geometry of the environment. Over time, however, the cells can acquire additional inputs, including inputs from more distal cues. This is manifest as a change in firing pattern ('remapping') when the new inputs are manipulated. Place cells also reorganize(More)
Hippocampal place cells support spatial memory using sensory information from the environment and self-motion information to localize their firing fields. Currently, there is disagreement about whether CA1 place cells can use pure self-motion information to disambiguate different compartments in environments containing multiple visually identical(More)
The subjective sense of space may result in part from the combined activity of place cells in the hippocampus and grid cells in posterior cortical regions such as the entorhinal cortex and pre- and parasubiculum. In horizontal planar environments, place cells provide focal positional information, whereas grid cells supply odometric (distance measuring)(More)
How entorhinal grids generate hippocampal place fields remains unknown. The simplest hypothesis-that grids of different scales are added together-cannot explain a number of place field phenomena, such as (1) Summed grids form a repeating, dispersed activation pattern whereas place fields are focal and nonrepeating; (2) Grid cells are active in all(More)
The role of context in guiding animal behavior has attracted increasing attention in recent years, but little is known about what constitutes a context, nor how and where in the brain it is represented. Contextual stimuli can take many forms, but of particular importance are those that collectively define a particular place or situation. The representation(More)
The role of the hippocampus in the representation of 'place' has been attributed to the place cells, whose spatially localised firing suggests their participation in forming a cognitive map of the environment. That this map is necessary for spatial memory formation is indicated by the propensity of almost all navigational tasks to be disrupted by(More)
How the brain represents represent large-scale, navigable space has been the topic of intensive investigation for several decades, resulting in the discovery that neurons in a complex network of cortical and subcortical brain regions co-operatively encode distance, direction, place, movement etc. using a variety of different sensory inputs. However, such(More)