eprintid: 10206261 rev_number: 9 eprint_status: archive userid: 699 dir: disk0/10/20/62/61 datestamp: 2025-03-19 14:18:03 lastmod: 2025-03-19 14:18:03 status_changed: 2025-03-19 14:18:03 type: article metadata_visibility: show sword_depositor: 699 creators_name: Ji, Zilong creators_name: Chu, Tianhao creators_name: Wu, Si creators_name: Burgess, Neil title: A systems model of alternating theta sweeps via firing rate adaptation ispublished: pub divisions: UCL divisions: B02 divisions: C07 divisions: D07 divisions: F81 keywords: Science & Technology, Life Sciences & Biomedicine, Biochemistry & Molecular Biology, Biology, Cell Biology, Life Sciences & Biomedicine - Other Topics, HEAD-DIRECTION CELLS, HIPPOCAMPAL-THETA, PHASE PRECESSION, ANTERIOR THALAMUS, SPATIAL MAP, GRID CELLS, RHYTHM, POSTSUBICULUM, DYNAMICS, NEURONS note: This work is licensed under a Creative Commons License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ abstract: Place and grid cells provide a neural system for self-location and tend to fire in sequences within each cycle of the hippocampal theta rhythm when rodents run on a linear track. These sequences correspond to the decoded location of the animal sweeping forward from its current location (“theta sweeps”). However, recent findings in open-field environments show alternating left-right theta sweeps and propose a circuit for their generation. Here, we present a computational model of this circuit, comprising theta-modulated head-direction cells, conjunctive grid × direction cells, and pure grid cells, based on continuous attractor dynamics, firing rate adaptation, and modulation by the medial-septal theta rhythm. Due to firing rate adaptation, the head-direction ring attractor exhibits left-right sweeps coding for internal direction, providing an input to the grid cell attractor network shifted along the internal direction, via an intermediate layer of conjunctive grid × direction cells, producing left-right sweeps of position by grid cells. Our model explains the empirical findings, including the alignment of internal position and direction sweeps and the dependence of sweep length on grid spacing. It makes predictions for theta-modulated head-direction cells, including relationships between theta phase precession during turning, theta skipping, anticipatory firing, and directional tuning width, several of which we verify in experimental data from anteroventral thalamus. The model also predicts relationships between position and direction sweeps, running speed, and dorsal-ventral location within the entorhinal cortex. Overall, a simple intrinsic mechanism explains the complex theta dynamics of an internal direction signal within the hippocampal formation, with testable predictions. date: 2025-02-24 date_type: published publisher: CELL PRESS official_url: https://doi.org/10.1016/j.cub.2024.08.059 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2362360 doi: 10.1016/j.cub.2024.08.059 medium: Print-Electronic pii: S0960-9822(24)01174-6 lyricists_name: Burgess, Neil lyricists_name: Ji, Zilong lyricists_id: NBURG72 lyricists_id: ZJIXX31 actors_name: Ji, Zilong actors_id: ZJIXX31 actors_role: owner full_text_status: public publication: Current Biology volume: 35 number: 4 pagerange: 709-722.e5 pages: 20 event_location: England citation: Ji, Zilong; Chu, Tianhao; Wu, Si; Burgess, Neil; (2025) A systems model of alternating theta sweeps via firing rate adaptation. Current Biology , 35 (4) 709-722.e5. 10.1016/j.cub.2024.08.059 <https://doi.org/10.1016/j.cub.2024.08.059>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10206261/1/Ji_1-s2.0-S0960982224011746-main.pdf