Data for: The hippocampal representation of context is preserved despite neural drift

The hippocampus is thought to mediate episodic memory through the
instantiation and reinstatement of context-specific cognitive maps.
However, recent longitudinal experiments have challenged this view,
reporting that most hippocampal cells change their tuning properties over
days even in the same environment. Often referred to as neural or
representational drift, these dynamics raise questions about the capacity
and content of the hippocampal code. One such question is whether and how
these long-term dynamics impact the hippocampal code for context. To
address this, we imaged large CA1 populations over more than a month of
daily experience as freely behaving mice participated in an extended
geometric morph paradigm. We find that long-timescale changes in
population activity occurred orthogonally to the representation of context
in network space, allowing for consistent readout of contextual
information across weeks. This population-level structure was supported by
heterogeneous patterns of activity at the level of individual cells, where
we observed evidence of a positive relationship between interpretable
contextual coding and long-term stability. Together, these results
demonstrate that long-timescale changes to the CA1 spatial code preserve
the relative structure of contextual representation.