Distinct Representations and Theta Dynamics in Dorsal and Ventral Hippocampus
Overview
Affiliations
Although anatomical, lesion, and imaging studies of the hippocampus indicate qualitatively different information processing along its septo-temporal axis, physiological mechanisms supporting such distinction are missing. We found fundamental differences between the dorsal (dCA3) and the ventral-most parts (vCA3) of the hippocampus in both environmental representation and temporal dynamics. Discrete place fields of dCA3 neurons evenly covered all parts of the testing environments. In contrast, vCA3 neurons (1) rarely showed continuous two-dimensional place fields, (2) differentiated open and closed arms of a radial maze, and (3) discharged similar firing patterns with respect to the goals, both on multiple arms of a radial maze and during opposite journeys in a zigzag maze. In addition, theta power and the fraction of theta-rhythmic neurons were substantially reduced in the ventral compared with dorsal hippocampus. We hypothesize that the spatial representation in the septo-temporal axis of the hippocampus is progressively decreased. This change is paralleled with a reduction of theta rhythm and an increased representation of nonspatial information.
Phase Precession Relative to Turning Angle in Theta-Modulated Head Direction Cells.
Ji Z, Lomi E, Jeffery K, Mitchell A, Burgess N Hippocampus. 2025; 35(2):e70008.
PMID: 40071745 PMC: 11898577. DOI: 10.1002/hipo.70008.
Calvin O, Erickson M, Walters C, Redish A PLoS Biol. 2025; 23(1):e3002954.
PMID: 39808614 PMC: 11731767. DOI: 10.1371/journal.pbio.3002954.
Hippocampal contextualization of social rewards in mice.
Duarte J, Nguyen R, Kyprou M, Li K, Milentijevic A, Cerquetella C Nat Commun. 2024; 15(1):9493.
PMID: 39489746 PMC: 11532361. DOI: 10.1038/s41467-024-53866-2.
Representations of stimulus meaning in the hippocampus.
Biane J, Ladow M, Fan A, Choi H, Zhou L, Hassan S bioRxiv. 2024; .
PMID: 39464010 PMC: 11507678. DOI: 10.1101/2024.10.14.618280.
Theta phase precession supports memory formation and retrieval of naturalistic experience in humans.
Zheng J, Yebra M, Schjetnan A, Patel K, Katz C, Kyzar M Nat Hum Behav. 2024; 8(12):2423-2436.
PMID: 39363119 PMC: 11659172. DOI: 10.1038/s41562-024-01983-9.