The firing rate of hippocampal CA1 place cells is modulated with a circadian period

Hippocampus ◽  
2011 ◽  
Vol 22 (6) ◽  
pp. 1325-1337 ◽  
Author(s):  
Robert G.K. Munn ◽  
David K. Bilkey
Keyword(s):  
Firing Rate ◽  
Place Cells ◽  
Circadian Period ◽  
Hippocampal Ca1

scholarly journals Interplay between somatic and dendritic inhibition promotes the emergence and stabilization of place fields

2018 ◽  
Author(s):  
Victor Pedrosa ◽  
Claudia Clopath
Keyword(s):  
Firing Rate ◽  
Place Cell ◽  
Place Cells ◽  
Place Field ◽  
Ca1 Neurons ◽  
Hippocampal Ca1 ◽  
Place Fields ◽  
Cell Stability ◽  
Cell Firing ◽  
Novel Environments

AbstractDuring exploration of novel environments, place fields are rapidly formed in hippocampal CA1 neurons. Place cell firing rate increases in early stages of exploration of novel environments but returns to baseline levels in familiar environments. However, although similar in amplitude and width, place fields in familiar environments are more stable than in novel environments. We propose a computational model of the hippocampal CA1 network, which describes the formation, the dynamics and the stabilization of place fields. We show that although somatic disinhibition is sufficient to form place cells, dendritic inhibition along with synaptic plasticity is necessary for stabilization. Our model suggests that place cell stability is due to large excitatory synaptic weights and large dendritic inhibition. We show that the interplay between somatic and dendritic inhibition balances the increased excitatory weights, so that place cells return to their baseline firing rate after exploration. Our model suggests that different types of interneurons are essential to unravel the mechanisms underlying place field plasticity. Finally, we predict that artificial induced dendritic events can shift place fields even after place field stabilization.

scholarly journals Alternating sequences of future and past behavior encoded within hippocampal theta oscillations

Science ◽  
2020 ◽  
Vol 370 (6513) ◽  
pp. 247-250 ◽  
Author(s):  
Mengni Wang ◽  
David J. Foster ◽  
Brad E. Pfeiffer
Keyword(s):  
Activity Patterns ◽  
Place Cells ◽  
Theta Oscillations ◽  
Retrospective Evaluation ◽  
Past Behavior ◽  
Hippocampal Ca1 ◽  
Ongoing Behavior ◽  
Theta Phase ◽  
Hippocampal Theta ◽  
And Storage

Neural networks display the ability to transform forward-ordered activity patterns into reverse-ordered, retrospective sequences. The mechanisms underlying this transformation remain unknown. We discovered that, during active navigation, rat hippocampal CA1 place cell ensembles are inherently organized to produce independent forward- and reverse-ordered sequences within individual theta oscillations. This finding may provide a circuit-level basis for retrospective evaluation and storage during ongoing behavior. Theta phase procession arose in a minority of place cells, many of which displayed two preferred firing phases in theta oscillations and preferentially participated in reverse replay during subsequent rest. These findings reveal an unexpected aspect of theta-based hippocampal encoding and provide a biological mechanism to support the expression of reverse-ordered sequences.

scholarly journals Assembly Responses of Hippocampal CA1 Place Cells Predict Learned Behavior in Goal-Directed Spatial Tasks on the Radial Eight-Arm Maze

Neuron ◽  
2019 ◽  
Vol 101 (1) ◽  
pp. 119-132.e4 ◽  
Author(s):  
Haibing Xu ◽  
Peter Baracskay ◽  
Joseph O’Neill ◽  
Jozsef Csicsvari
Keyword(s):  
Place Cells ◽  
Learned Behavior ◽  
Hippocampal Ca1 ◽  
Spatial Tasks

scholarly journals Asymmetry of the temporal code for space by hippocampal place cells

2016 ◽  
Author(s):  
Bryan C. Souza ◽  
Adriano B. L. Tort
Keyword(s):  
Firing Rate ◽  
Spatial Information ◽  
Place Cells ◽  
Spike Timing ◽  
Temporal Coding ◽  
Place Field ◽  
Phase Precession ◽  
Wide Debate ◽  
Rate Coding ◽  
Theta Phase

Hippocampal place cells convey spatial information through spike frequency (“rate coding”) and spike timing relative to the theta phase (“temporal coding”). Whether rate and temporal coding are due to independent or related mechanisms has been the subject of wide debate. Here we show that the spike timing of place cells couples to theta phase before major increases in firing rate, anticipating the animal’s entrance into the classical, rate-based place field. In contrast, spikes rapidly decouple from theta as the animal leaves the place field and firing rate decreases. Therefore, temporal coding has strong asymmetry around the place field center. We further show that the dynamics of temporal coding along space evolves in three stages: phase coupling, phase precession and phase decoupling. These results suggest that place cells represent more future than past locations through their spike timing and that independent mechanisms govern rate and temporal coding.

scholarly journals Conjunctive spatial and idiothetic codes are topographically organized in the lateral septum

2020 ◽  
Author(s):  
Suzanne van der Veldt ◽  
Guillaume Etter ◽  
Fernanda Sosa ◽  
Coralie-Anne Mosser ◽  
Sylvain Williams
Keyword(s):  
Medial Septum ◽  
Place Cells ◽  
Lateral Septum ◽  
Head Direction ◽  
Neuronal Populations ◽  
Spatial Tuning ◽  
Hippocampal Ca1 ◽  
Memory Network ◽  
Anterior Posterior

AbstractThe relevance of the hippocampal spatial code for downstream neuronal populations – in particular its main subcortical output, the lateral septum (LS) - is still poorly understood. Here, we addressed this knowledge gap by first clarifying the organization of LS afferents and efferents via retrograde and anterograde trans-synaptic tracing. We found that mouse LS receives inputs from hippocampal subregions CA1, CA3, and subiculum, and in turn projects directly to the lateral hypothalamus (LH), ventral tegmental area (VTA), and medial septum (MS). Next, we functionally characterized the spatial tuning properties of LS GABAergic cells, the principal cells composing the LS, via calcium imaging combined with unbiased analytical methods. We identified a significant number of cells that are modulated by place (38.01%), speed (23.71%), acceleration (27.84%), and head-direction (23.09%), and conjunctions of these properties, with spatial tuning comparable to hippocampal CA1 and CA3 place cells. Bayesian decoding of position on the basis of LS place cells accurately reflected the location of the animal. The distributions of cells exhibiting these properties formed gradients along the anterior-posterior axis of the LS, directly reflecting the organization of hippocampal inputs to the LS. A portion of LS place cells showed stable fields over the course of multiple days, potentially reflecting long-term episodic memory. Together, our findings demonstrate that the LS accurately and robustly represents spatial and idiothetic information and is uniquely positioned to relay this information from the hippocampus to the VTA, LH, and MS, thus occupying a key position within this distributed spatial memory network.

scholarly journals Prefrontal cortical activity predicts the extra-place field spiking of hippocampal place cells

2020 ◽  
Author(s):  
Jai Y. Yu ◽  
Loren M. Frank
Keyword(s):  
Receptive Field ◽  
Receptive Fields ◽  
Cortical Activity ◽  
Place Cells ◽  
Theta Oscillations ◽  
Place Field ◽  
Prefrontal Cortical ◽  
Hippocampal Ca1 ◽  
Non Local ◽  
Hippocampal Theta

AbstractThe receptive field of a neuron describes the regions of a stimulus space where the neuron is consistently active. Sparse spiking outside of the receptive field is often considered to be noise, rather than a reflection of information processing. Whether this characterization is accurate remains unclear. We therefore contrasted the sparse, temporally isolated spiking of hippocampal CA1 place cells to the consistent, temporally adjacent spiking seen within their spatial receptive fields (“place fields”). We found that isolated spikes, which occur during locomotion, are more strongly phase coupled to hippocampal theta oscillations than adjacent spikes and, surprisingly, transiently express coherent representations of non-local spatial representations. Further, prefrontal cortical activity is coordinated with, and can predict the occurrence of future isolated spiking events. Rather than local noise within the hippocampus, sparse, isolated place cell spiking reflects a coordinated cortical-hippocampal process consistent with the generation of non-local scenario representations during active navigation.

scholarly journals Dorsal CA1 Hippocampal Place Cells Form a Multi-Scale Representation of Megaspace

2021 ◽  
Author(s):  
B.C. Harland ◽  
M. Contreras ◽  
M. Souder ◽  
J.M. Fellous
Keyword(s):  
Spatial Representation ◽  
Dorsal Hippocampus ◽  
Place Cells ◽  
Coarse Grained ◽  
Natural Environments ◽  
Multi Scale ◽  
Coding Scheme ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Hippocampal Ca1

Spatially firing “place cells” within the hippocampal CA1 region form internal maps of the environment necessary for navigation and memory. In rodents, these neurons have been almost exclusively studied in small environments (<4 m2). It remains unclear how place cells encode a very large open 2D environment, which is more analogous to the natural environments experienced by rodents and other mammals. Such an ethologically realistic environment would require a more complex spatial representation, capable of simultaneously representing space at overlapping multiple fine to coarse informational scales. Here we show that in a ‘megaspace’ (18.6 m2), the majority of dorsal CA1 place cells exhibited multiple place subfields of different sizes, akin to those observed along the septo-temporal axis. Furthermore, the total area covered by the subfields of each cell was not correlated with the number of subfields, and this total area increased with the scale of the environment. The multiple different-sized subfields exhibited by place cells in the megaspace suggest that the ensemble population of subfields form a multi-scale representation of space within the dorsal hippocampus. Our findings point to a new dorsal hippocampus ensemble coding scheme that simultaneously supports navigational processes at both fine- and coarse-grained resolutions.

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