Spatial remapping in the subicular complex and entorhinal cortex follows low-dimensional geometric principles.

Area of Science:

• Neuroscience
• Cognitive Science
• Spatial Navigation

Background:

• Neurons in the hippocampal formation create cognitive maps of environments.
• Spatial representations (remapping) change between environments, but the transformation principle is unknown.

Purpose of the Study:

• To investigate if spatial representations across different environments follow a systematic transformation principle.
• To determine if coordinate transformations can relate spatial representations across rooms.

Main Methods:

• Recorded large neuronal populations from the subicular complex and entorhinal cortex in mice.
• Mice navigated environments of varying geometries.
• Analyzed population-level decoding to identify coordinate transformations.

Main Results:

• Despite heterogeneous single-cell remapping, population decoding revealed a consistent low-dimensional affine transformation.
• This transformation included rotation, scaling, shear, reflection, and translation.
• Complex neural remapping simplifies to a geometric rule at the population level.

Conclusions:

• The hippocampal formation uses a structured internal coordinate template adaptable to environmental geometry.
• This adaptable template may function as an internal model of space.
• Spatial map transitions follow systematic geometric principles, not unconstrained reorganization.