Work

Time cell sequences during delay intervals are not dependent on brain state and do not support hippocampus-dependent working memory

Year: 2025

Type: article

Abstract: Working memory (WM) is essential for performing cognitive tasks, and sequentially active hippocampal cells over many seconds ('time cells') have been observed during WM retention. Time cells predominantly occur when neural activity oscillates at theta frequency. To examine whether time cells during WM maintenance depend on ongoing theta oscillations, we controlled the persistence of theta during 10 s and 30 s delay intervals by either having rats run or rest, which resulted in conditions with and without persistent theta oscillations. In either condition, reliable time cells were limited to only the first few seconds of the delay interval while a second population of constitutively active cells emerged during the remainder of the delay period, neither of which were memory-related. Our results show that hippocampal sequential activity patterns are short-lasting and uninformative for WM, and that WM retention over more than ~5 s needs to include mechanisms other than hippocampal time cells.

Source: Nature Communications

DOI: 10.1038/s41467-025-62498-z

Authors: Li Yuan, Jose F. Figueroa, Ameen Khan, Gautam Narayan, Jill K. Leutgeb, Stefan Leutgeb

Institutions: University of California San Diego, Institute for Advanced Study

Language: English

Topic: Memory and Neural Mechanisms

Subfield: Cognitive Neuroscience

Field: Neuroscience

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $6,990

Funders: U.S. Department of Health and Human Services, National Institutes of Health, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke