Article
Neurosciences
Noah L. Pettit, Xintong C. Yuan, Christopher D. Harvey
Summary: The expression of spatial maps in the hippocampus can be modulated by the internal state of an animal, resulting in changes even without changes to the external world.
NATURE NEUROSCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Eleonore Duvelle, Roddy M. Grieves, Anyi Liu, Selim Jedidi-Ayoub, Joanna Holeniewska, Adam Harris, Nils Nyberg, Francesco Donnarumma, Julie M. Lefort, Kate J. Jeffery, Christopher Summerfield, Giovanni Pezzulo, Hugo J. Spiers
Summary: The study found that the dorsal CA1 place cells of rats have limited ability to encode environmental connectivity, primarily coding location in a global reference frame with minimal response to doorways and other locations.
Article
Multidisciplinary Sciences
Lu Zhang, Julien Fournier, Mehdi Fallahnezhad, Anne-Lise Paradis, Christelle Rochefort, Laure Rondi-Reig
Summary: The cerebellum plays a critical role in the development of foraging strategies, with impaired PKC-dependent cerebellar functions leading to a random foraging strategy in mice. In contrast, control mice adopt a spatial sequence repetition strategy to maximize rewards. The cerebellum also controls how self-motion cues affect the selectivity of place cells to position and direction. Therefore, the cerebellum contributes to the development of optimal sequential paths during foraging by modulating self-motion and theta signals for place cell coding.
Review
Behavioral Sciences
Genela Morris, Dori Derdikman
Summary: Place cells and grid cells are essential for the hippocampal cognitive map. The traditional forward model suggests that grid cells are generated by a continuous attractor network, with a velocity signal moving entorhinal activity bumps during locomotion, and place cell activity being the sum of entorhinal grid cell modules. Experimental data support the first hypothesis but not the latter two. A modified model (spatial modulation continuous attractor network; SCAN) is proposed, where place cells are generated from spatially selective non-grid cells, and locomotion causes the movement of the hippocampal activity bump and the entorhinal manifolds. This inversion aligns with the shift of hippocampal function from navigation to more abstract processes.
TRENDS IN COGNITIVE SCIENCES
(2023)
Article
Cell Biology
Prannoy Chaudhuri-Vayalambrone, Michael Everett Rule, Marius Bauza, Marino Krstulovic, Pauline Kerekes, Stephen Burton, Timothy O'Leary, Julija Krupic
Summary: Grid cells and place cells in freely foraging rats were co-recorded, revealing that grid cells have prospective time shifts proportional to their spatial scale, providing an instantaneous readout of increasing time horizons. Place cells have larger time shifts compared to grid cells and also increase with place field sizes. Time horizons are modulated non-linearly by the animal's trajectories in relation to the local boundaries and locomotion cues. Long and short time horizons occur at different parts of the theta cycle, possibly facilitating their readout. These findings suggest that grid and place cell population activity represents local trajectories essential for goal-directed navigation and planning.
Article
Computer Science, Artificial Intelligence
Adithya Krishna, Divyansh Mittal, Siri Garudanagiri Virupaksha, Abhishek Ramdas Nair, Rishikesh Narayanan, Chetan Singh Thakur
Summary: The research has successfully implemented algorithmic and hardware structures mimicking the mammalian spatial navigation system, incorporating grid-cell, place-cell, and decoding modules in a multi-layer architecture to achieve navigation and path integration.
Article
Multidisciplinary Sciences
Jake Ormond, John O'Keefe
Summary: The hippocampus plays a crucial role in supporting flexible navigation by encoding location information in a vector-based model, allowing animals to select optimal paths to reach their goals.
Article
Multidisciplinary Sciences
Lu Zhang, Stephanie M. Prince, Abigail L. Paulson, Annabelle C. Singer
Summary: This study investigates the role of nonplace cells in memory-guided navigation when spatial cues provide ambiguous information. It is found that nonplace cells differentiate between ambiguous spatial cues and show altered activity and modulation at task-relevant cues. This discrimination is absent in a mouse model of Alzheimer's disease.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Computer Science, Artificial Intelligence
Tristan Baumann, Hanspeter A. Mallot
Summary: The firing fields of hippocampal place cells, known as remapping, change when a rat enters a new compartment in a maze. Remapping cannot be explained solely by path integration and local sensory cues, but requires additional context recognition at gateways between compartments. A model is proposed where place and grid cells follow a joint attractor dynamic, depending on each other's activity and resetting during remapping triggered by passage through a gateway.
Article
Neurosciences
Yanbo Lian, Anthony N. Burkitt
Summary: This study demonstrates how theta phase precession in hippocampal place cells can emerge from medial entorhinal cortex (MEC) input, explaining the spatial and temporal properties of these cells. The MEC grid cells predominantly determine the temporal response properties of hippocampal place cells in this study.
Article
Biochemistry & Molecular Biology
Bruce Harland, Marco Contreras, Madeline Souder, Jean-Marc Fellous
Summary: In a large open environment, most dorsal CA1 place cells exhibit multiple place subfields of different sizes, suggesting a multi-scale representation of space within the dorsal hippocampus.
Article
Multidisciplinary Sciences
Jason J. Moore, Jesse D. Cushman, Lavanya Acharya, Briana Popeney, Mayank R. Mehta
Summary: The hippocampus plays a crucial role in spatial navigation, Hebbian synaptic plasticity, spatial selectivity, and episodic memory, yet the exact relationship between these functions remains unclear. Hippocampal neurons exhibit multiplexed selectivity while rats perform virtual navigation tasks, encoding path distance and head angle with weak allocentric spatial components. Neural activity in the hippocampus shows increased clustering and becomes better predictors of behaviorally relevant variables, supporting navigation and encoding journey-specific episodes through Hebbian plasticity.
Article
Cell Biology
Brad A. Radvansky, Jun Young Oh, Jason R. Climer, Daniel A. Dombeck
Summary: This study shows that the hippocampus in mice does not map space as a single coherent physical variable, but rather as a combination of sensory and abstract reference frames determined by the subject's behavioral goal. Different behavioral tasks lead to global remapping in the hippocampus, adapting to different spatial information modalities.
Article
Biology
Man Yi Yim, Lorenzo A. Sadun, Ila R. Fiete, Thibaud Taillefumier
Summary: The study suggests that grid-driven place field arrangements are strongly constrained by structured inputs, and altering weights can affect existing arrangements, explaining the volatility of the place code.
Article
Biology
Mi-Seon Kong, Eun Joo Kim, Sanggeon Park, Larry S. Zweifel, Yeowool Huh, Jeiwon Cho, Jeansok J. Kim
Summary: The study found dynamic interaction between fear signaling cells in the basal amygdala (BA) and spatial coding cells in the dorsal hippocampus (dHPC) as animals traverse safe and danger areas in their environment. Only when dHPC cells synchronized with predator-responsive BA cells did they significantly remap as risk locations escalated.