Grid-cell modules remain coordinated when neural activity is dissociated from external sensory cues

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• The medial entorhinal cortex (MEC) contains grid cells that form a cognitive map for spatial navigation.
• Grid cell representations are organized into modules with different spatial scales, and their population activity is coordinated within modules.
• Coordination across modules, however, remains poorly understood.

Purpose of the Study:

• To investigate the coordination of activity patterns across different grid cell modules in the MEC.
• To determine if this coordination persists under conditions where sensory cues are absent or disrupted.

Main Methods:

• Simultaneous recordings of hundreds of grid cells in freely foraging animals.
• Analysis of joint activity patterns in the light (with sensory cues) versus darkness (disrupted sensory cues).

Main Results:

• Grid cell modules exhibit tight coordination of their activity states, irrespective of environmental lighting conditions.
• This coordination is maintained even when the internal spatial representation deviates from the animal's actual position in darkness.

Conclusions:

• Internal brain mechanisms dynamically coordinate grid cell modules in the MEC.
• This coordinated activity ensures a coherent and smooth neural representation of an animal's trajectory, independent of external sensory input.