Optogenetic reduction of theta oscillations induces remapping of time cells without memory impairment.

Optogenetic reduction of hippocampal theta oscillations causes remapping and recruitment of time cells without impairing spatial working memory.

• Why it matters: Understanding how hippocampal theta oscillations support working memory and time cell sequences is crucial for deciphering memory mechanisms, yet causal links are unclear.
• What they did: Researchers used optogenetics to silence the medial septal GABAergic theta-generating circuit during the delay period of a spatial working memory task, observing effects on hippocampal time cells.
• The result: Despite substantial reduction in theta oscillations leading to remapping and new time cell recruitment, behavioral performance and trajectory-specific coding remained intact, indicating task-relevant information persists under theta disruption.