Multiple Maps of the Same Spatial Context Can Stably Coexist in the Mouse Hippocampus

Area of Science:

• Neuroscience
• Cognitive Science
• Memory Research

Background:

• Hippocampal place cells are crucial for spatial memory, typically showing stable activity in familiar environments.
• Previous research indicated place cells remap across different contexts but maintain tuning within a single, familiar context.

Purpose of the Study:

• To investigate whether hippocampal neurons can form multiple distinct representations of the same familiar environment.
• To explore the nature and persistence of these multiple representations.

Main Methods:

• Recording neuronal activity in mouse hippocampi during exploration of a familiar environment.
• Analyzing place cell firing patterns across multiple separate visits to the environment.
• Assessing the spatial information content and stability of neuronal representations over time.

Main Results:

• Mouse hippocampal neurons demonstrated global remapping, forming multiple distinct spatial maps of the same environment.
• Map alternations occurred only between separate visits, suggesting switching between stable network attractors.
• These distinct maps were spatially informative and persisted for weeks, indicating reliable storage and retrieval.

Conclusions:

• A single familiar spatial context can be represented by multiple distinct neuronal maps in the hippocampus.
• These multiple representations are stable, informative, and potentially stored in long-term memory.
• This challenges the notion of a single, fixed neural representation for a given spatial context.