scholarly journals Phase precession in the human hippocampus and entorhinal cortex

2020 ◽  
Author(s):  
Salman E. Qasim ◽  
Itzhak Fried ◽  
Joshua Jacobs
Keyword(s):  
Entorhinal Cortex ◽  
Spatial Information ◽  
Neural Representation ◽  
Local Network ◽  
Neuron Activity ◽  
Human Hippocampus ◽  
Phase Precession ◽  
Show Evidence ◽  
Theta Phase ◽  
Theta Phase Precession

AbstractKnowing where we are, where we have been, and where we are going is critical to many behaviors, including navigation and memory. One potential neuronal mechanism underlying this ability is phase precession, in which spatially tuned neurons represent sequences of positions by activating at progressively earlier phases of local network theta (~5–10 Hz) oscillations. Phase precession may be a general neural pattern for representing sequential events for learning and memory. However, phase precession has never been observed in humans. By recording human single-neuron activity during spatial navigation, we show that spatially tuned neurons in the human hippocampus and entorhinal cortex exhibit phase precession. Furthermore, beyond the neural representation of locations, we show evidence for phase precession related to specific goal-states. Our findings thus extend theta phase precession to humans and suggest that this phenomenon has a broad functional role for the neural representation of both spatial and non-spatial information.

scholarly journals Distinct hippocampal network states support theta phase precession and theta sequences in CA1

2021 ◽  
Author(s):  
Matteo Guardamagna ◽  
Federico Stella ◽  
Francesco P. Battaglia
Keyword(s):  
Spatial Information ◽  
Place Cells ◽  
Temporal Coding ◽  
Temporal Code ◽  
Network State ◽  
Phase Precession ◽  
Hippocampal Network ◽  
Theta Phase ◽  
Network States ◽  
Theta Phase Precession

The hippocampus likely uses temporal coding to represent complex memories via mechanisms such as theta phase precession and theta sequences. Theta sequences are rapid sweeps of spikes from multiple place cells, encoding past or planned trajectories or non-spatial information. Phase precession, the correlation between a place cell's theta firing phase and animal position has been suggested to facilitate sequence emergence. We find that CA1 phase precession varies strongly across cells and environmental contingencies. Phase precession depends on the CA1 network state, and is only present when the medium gamma oscillation (60-90 Hz, linked to Entorhinal inputs) dominates. Conversely, theta sequences are most evident for non-precessing cells or with leading slow gamma (20-45 Hz, linked to CA3 inputs). These results challenge the view that phase precession is the mechanism underlying the emergence of theta sequences and point at a 'dual network states' model for hippocampal temporal code, potentially supporting merging of memory and exogenous information in CA1.

scholarly journals Theta phase precession beyond the hippocampus

2012 ◽  
Vol 23 (1) ◽  
Author(s):  
Sushant Malhotra ◽  
Robert W.A. Cross ◽  
Matthijs A.A. van der Meer
Keyword(s):  
Phase Precession ◽  
Theta Phase ◽  
Theta Phase Precession

Cognitive Map Formation Through Sequence Encoding by Theta Phase Precession

2004 ◽  
Vol 16 (12) ◽  
pp. 2665-2697 ◽  
Author(s):  
Hiroaki Wagatsuma ◽  
Yoko Yamaguchi
Keyword(s):  
Field Potential ◽  
Computer Experiments ◽  
Cognitive Map ◽  
Phase Precession ◽  
Spatial Environment ◽  
Hippocampal Network ◽  
Theta Phase ◽  
Space Coding ◽  
Temporal Sequences ◽  
Theta Phase Precession

The rodent hippocampus has been thought to represent the spatial environment as a cognitive map. The associative connections in the hippocampus imply that a neural entity represents the map as a geometrical network of hippocampal cells in terms of a chart. According to recent experimental observations, the cells fire successively relative to the theta oscillation of the local field potential, called theta phase precession, when the animal is running. This observation suggests the learning of temporal sequences with asymmetric connections in the hippocampus, but it also gives rather inconsistent implications on the formation of the chart that should consist of symmetric connections for space coding. In this study, we hypothesize that the chart is generated with theta phase coding through the integration of asymmetric connections. Our computer experiments use a hippocampal network model to demonstrate that a geometrical network is formed through running experiences in a few minutes. Asymmetric connections are found to remain and distribute heterogeneously in the network. The obtained network exhibits the spatial localization of activities at each instance as the chart does and their propagation that represents behavioral motions with multidirectional properties. We conclude that theta phase precession and the Hebbian rule with a time delay can provide the neural principles for learning the cognitive map.

Memory Encoding by Theta Phase Precession in the Hippocampal Network

2003 ◽  
Vol 15 (10) ◽  
pp. 2379-2397 ◽  
Author(s):  
Naoyuki Sato ◽  
Yoko Yamaguchi
Keyword(s):  
Spike Timing ◽  
Temporal Sequence ◽  
Memory Storage ◽  
Trial Experience ◽  
Phase Precession ◽  
Rate Coding ◽  
Hippocampal Network ◽  
Theta Phase ◽  
Theta Phase Precession

Recent experimental evidence on spike-timing-dependent plasticity and on phase precession (i.e., the theta rhythm dependent firing of rat hippocampalcells) associates the contribution of phase precession to episodic memory. This article aims at clarifying the role of phase precession in memory storage. Computer simulations show that the memory storage in the behavioral timescale varies in timescale of the temporal sequence from half a second to several seconds. In contrast, the memory storage caused by traditional rate coding is restricted to the temporal sequence within 40 ms. During phase precession, memory storage of a single trial experience is possible, even in the presence of noise. It is therefore concluded that encoding by phase precession is appropriate for memory storage of the temporal sequence in the behavioral timescale.

Sign in / Sign up

Export Citation Format

Share Document