scholarly journals On information metrics for spatial coding

2017 ◽  
Author(s):  
Bryan C. Souza ◽  
Rodrigo Pavão ◽  
Hindiael Belchior ◽  
Adriano B.L. Tort
Keyword(s):  
Mutual Information ◽  
Spatial Information ◽  
Hippocampal Formation ◽  
Standard Procedure ◽  
Real Data ◽  
Place Cells ◽  
Spatial Coding ◽  
Neuronal Populations ◽  
Information Metric ◽  
Information Metrics

AbstractThe hippocampal formation is involved in navigation, and its neuronal activity exhibits a variety of spatial correlates (e.g., place cells, grid cells). The quantification of the information encoded by spikes has been standard procedure to identify which cells have spatial correlates. For place cells, most of the established metrics derive from Shannon’s mutual information (Shannon, 1948), and convey information rate in bits/sec or bits/spike (Skaggs et al., 1993; Skaggs et al., 1996). Despite their widespread use, the performance of these metrics in relation to the original mutual information metric has never been investigated. In this work, using simulated and real data, we find that the current information metrics correlate less with the accuracy of spatial decoding than the original mutual information metric. We also find that the top informative cells may differ among metrics, and show a surrogate-based normalization that yields comparable spatial information estimates. Since different information metrics may identify different neuronal populations, we discuss current and alternative definitions of spatially informative cells, which affect the metric choice.

scholarly journals Experience-dependent trends in CA1 theta and slow gamma rhythms in freely behaving mice

2018 ◽  
Vol 119 (2) ◽  
pp. 476-489 ◽  
Author(s):  
Brian J. Gereke ◽  
Alexandra J. Mably ◽  
Laura Lee Colgin
Keyword(s):  
Spatial Information ◽  
Hippocampal Formation ◽  
Cell Activity ◽  
Place Cell ◽  
Place Cells ◽  
Running Speed ◽  
Circular Track ◽  
Gamma Rhythms ◽  
Over Time ◽  
First Session

CA1 place cells become more anticipatory with experience, an effect thought to be caused by NMDA receptor-dependent plasticity in the CA3–CA1 network. Theta (~5–12 Hz), slow gamma (~25–50 Hz), and fast gamma (~50–100 Hz) rhythms are thought to route spatial information in the hippocampal formation and to coordinate place cell ensembles. Yet, it is unknown whether these rhythms exhibit experience-dependent changes concurrent with those observed in place cells. Slow gamma rhythms are thought to indicate inputs from CA3 to CA1, and such inputs are thought to be strengthened with experience. Thus, we hypothesized that slow gamma rhythms would become more evident with experience. We tested this hypothesis using mice freely traversing a familiar circular track for three 10-min sessions per day. We found that slow gamma amplitude was reduced in the early minutes of the first session of each day, even though both theta and fast gamma amplitudes were elevated during this same period. However, in the first minutes of the second and third sessions of each day, all three rhythms were elevated. Interestingly, theta was elevated to a greater degree in the first minutes of the first session than in the first minutes of later sessions. Additionally, all three rhythms were strongly influenced by running speed in dynamic ways, with the influence of running speed on theta and slow gamma changing over time within and across sessions. These results raise the possibility that experience-dependent changes in hippocampal rhythms relate to changes in place cell activity that emerge with experience. NEW & NOTEWORTHY We show that CA1 theta, slow gamma, and fast gamma rhythms exhibit characteristic changes over time within sessions in familiar environments. These effects in familiar environments evolve across repeated sessions.

scholarly journals Place cells in head-fixed mice navigating a floating real-world environment

2020 ◽  
Author(s):  
Mary Ann Go ◽  
Jake Rogers ◽  
Giuseppe P. Gava ◽  
Catherine Davey ◽  
Seigfred Prado ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Real World ◽  
Spatial Information ◽  
Memory Function ◽  
Place Cells ◽  
Neural Population ◽  
Spatial Coding ◽  
Place Fields ◽  
Freely Moving ◽  
World Environment

ABSTRACTThe hippocampal place cell system in rodents has provided a major paradigm for the scientific investigation of memory function and dysfunction. Place cells have been observed in area CA1 of the hippocampus of both freely moving animals, and of head-fixed animals navigating in virtual reality environments. However, spatial coding in virtual reality preparations has been observed to be impaired. Here we show that the use of a real-world environment system for head-fixed mice, consisting of a track floating on air, provides some advantages over virtual reality systems for the study of spatial memory. We imaged the hippocampus of head-fixed mice injected with the genetically encoded calcium indicator GCaMP6s while they navigated circularly constrained or open environments on the floating platform. We observed consistent place tuning in a substantial fraction of cells with place fields remapping when animals entered a different environment. When animals re-entered the same environment, place fields typically remapped over a time period of multiple days, faster than in freely moving preparations, but comparable with virtual reality. Spatial information rates were within the range observed in freely moving mice. Manifold analysis indicated that spatial information could be extracted from a low-dimensional subspace of the neural population dynamics. This is the first demonstration of place cells in head-fixed mice navigating on an air-lifted real-world platform, validating its use for the study of brain circuits involved in memory and affected by neurodegenerative disorders.

scholarly journals Burst firing and spatial coding in subicular principal cells

2018 ◽  
Author(s):  
Jean Simonnet ◽  
Michael Brecht
Keyword(s):  
Spatial Information ◽  
Hippocampal Formation ◽  
Cell Types ◽  
Burst Firing ◽  
Spatial Coding ◽  
Bursting Neurons ◽  
Output Structure ◽  
Distinct Unit

AbstractThe subiculum is the major output structure of the hippocampal formation and is involved in learning and memory as well as in spatial navigation. Little is known about how the cellular diversity of subicular neurons is related to function. Primed by in vitro studies, which identified distinct bursting patterns in subicular cells, we asked how subicular burst firing is related to spatial coding in vivo. Using high-resolution juxtacellular recordings in freely moving rats, we analyzed the firing patterns of 51 subicular principal neurons and distinguished two populations based on their bursting behavior, i.e. sparsely bursting (∼80%) and dominantly bursting neurons (∼20%). Dominantly bursting neurons had significantly higher firing rates than sparsely bursting neurons. Furthermore, the two clusters had distinct spatial properties, sparsely bursting cells showing strong positional tuning and dominantly bursting cells being only weakly tuned. Additionally, the occurrence of bursts in sparsely bursting neurons defined well-defined spatial fields. In contrast, isolated spikes contained less spatial information. We conclude that burst firing distinguishes subicular principal cell types and constitutes a distinct unit encoding spatial information in sparsely bursting spatial cells. Overall, our results demonstrate that burst firing is highly relevant to subicular space coding.

scholarly journals Place Cells in Head-Fixed Mice Navigating a Floating Real-World Environment

2021 ◽  
Vol 15 ◽  
Author(s):  
Mary Ann Go ◽  
Jake Rogers ◽  
Giuseppe P. Gava ◽  
Catherine E. Davey ◽  
Seigfred Prado ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Real World ◽  
Spatial Information ◽  
Memory Function ◽  
Place Cells ◽  
Neural Population ◽  
Spatial Coding ◽  
Place Fields ◽  
Freely Moving ◽  
World Environment

The hippocampal place cell system in rodents has provided a major paradigm for the scientific investigation of memory function and dysfunction. Place cells have been observed in area CA1 of the hippocampus of both freely moving animals, and of head-fixed animals navigating in virtual reality environments. However, spatial coding in virtual reality preparations has been observed to be impaired. Here we show that the use of a real-world environment system for head-fixed mice, consisting of an air-floating track with proximal cues, provides some advantages over virtual reality systems for the study of spatial memory. We imaged the hippocampus of head-fixed mice injected with the genetically encoded calcium indicator GCaMP6s while they navigated circularly constrained or open environments on the floating platform. We observed consistent place tuning in a substantial fraction of cells despite the absence of distal visual cues. Place fields remapped when animals entered a different environment. When animals re-entered the same environment, place fields typically remapped over a time period of multiple days, faster than in freely moving preparations, but comparable with virtual reality. Spatial information rates were within the range observed in freely moving mice. Manifold analysis indicated that spatial information could be extracted from a low-dimensional subspace of the neural population dynamics. This is the first demonstration of place cells in head-fixed mice navigating on an air-lifted real-world platform, validating its use for the study of brain circuits involved in memory and affected by neurodegenerative disorders.

scholarly journals Choice of method of place cell classification determines the population of cells identified

2021 ◽  
Vol 17 (7) ◽  
pp. e1008835
Author(s):  
Dori M. Grijseels ◽  
Kira Shaw ◽  
Caswell Barry ◽  
Catherine N. Hall
Keyword(s):  
Spatial Information ◽  
Real Data ◽  
Place Cell ◽  
Place Cells ◽  
Optical Methods ◽  
Combination Method ◽  
Cell Detection ◽  
Imaging Data ◽  
Place Field ◽  
Implanted Electrodes

Place cells, spatially responsive hippocampal cells, provide the neural substrate supporting navigation and spatial memory. Historically most studies of these neurons have used electrophysiological recordings from implanted electrodes but optical methods, measuring intracellular calcium, are becoming increasingly common. Several methods have been proposed as a means to identify place cells based on their calcium activity but there is no common standard and it is unclear how reliable different approaches are. Here we tested four methods that have previously been applied to two-photon hippocampal imaging or electrophysiological data, using both model datasets and real imaging data. These methods use different parameters to identify place cells, including the peak activity in the place field, compared to other locations (the Peak method); the stability of cells’ activity over repeated traversals of an environment (Stability method); a combination of these parameters with the size of the place field (Combination method); and the spatial information held by the cells (Information method). The methods performed differently from each other on both model and real data. In real datasets, vastly different numbers of place cells were identified using the four methods, with little overlap between the populations identified as place cells. Therefore, choice of place cell detection method dramatically affects the number and properties of identified cells. Ultimately, we recommend the Peak method be used in future studies to identify place cell populations, as this method is robust to moderate variations in place field within a session, and makes no inherent assumptions about the spatial information in place fields, unless there is an explicit theoretical reason for detecting cells with more narrowly defined properties.

scholarly journals Discrete Place Fields of Hippocampal Formation Interneurons

2007 ◽  
Vol 97 (6) ◽  
pp. 4152-4161 ◽  
Author(s):  
W. Bryan Wilent ◽  
Douglas A. Nitz
Keyword(s):  
Spatial Information ◽  
Hippocampal Formation ◽  
Brain Regions ◽  
Place Cells ◽  
Informational Content ◽  
Inhibitory Interneurons ◽  
Spike Discharge ◽  
Principal Cells ◽  
Place Fields ◽  
Spatial Specificity

The spike discharge of hippocampal excitatory principal cells, also called “place cells,” is highly location specific, but the discharge of local inhibitory interneurons is thought to display relatively low spatial specificity. Whereas in other brain regions, such as sensory neocortex, the activity of interneurons is often exquisitely stimulus selective and directly determines the responses of neighboring excitatory neurons, the activity of hippocampal interneurons typically lacks the requisite specificity needed to shape the defined structure of principal cell fields. Here we show that hippocampal formation interneurons have “on” fields (abrupt increases in activity) and “off” fields (abrupt decreases in activity) that are associated with the same location-specific informational content, spatial resolution, and dependency on context as the “place fields” of CA1 principal cells. This establishes that interneurons have well-defined place fields, thus having important implications for understanding how the hippocampus represents spatial information.

Are mom-and-pop and professional hosts actually competing against hotels?

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ruggero Sainaghi ◽  
Rodolfo Baggio
Keyword(s):  
Mutual Information ◽  
Design Methodology ◽  
Management Policy ◽  
Seasonal Patterns ◽  
Content Type ◽  
Rhythmic Behavior ◽  
Direct Competition ◽  
Information Metric ◽  
Fierce Competition ◽  
Practical Implications

Purpose This paper aims to examine the question of whether commercial, peer-to-peer accommodation platforms (Airbnb, in particular) and hotels are in fierce competition with each other with the possible presence of substitution threats, and compares the time series of the occupancy values across two supplier types. Design/methodology/approach The cities of Milan and Rome are used as case studies for this analysis. To assess the extent of synchronization, the series of Airbnb and hotels are transformed into a series of symbols that render their rhythmic behavior, and a mutual information metric is used to measure the effect. Findings The results show that Airbnb hosts and hotels have different seasonal patterns. The diverse occupancy trends support the absence of direct competition between Airbnb and hotels. The findings are consistent in the two analyzed cities (Milan and Rome). Interestingly, there are higher similarities between seasonal occupancy series of Airbnb listings in Milan and Rome, on one side, and hotels in Milan and Rome, on the other, than between Airbnb and hotels in the same city. Research limitations/implications The findings show a progressive de-synchronization (within mutual information) among the five groups of Airbnb hosts triggered by the rising professionalization degree. This result suggests the existence of a partial different business model for multi-listing hosts. Practical implications The study illustrates an absence of any substitution threat between Airbnb and hotels in both cities. This could have important consequences, especially for the pricing and revenue management policy. In fact, the higher the substitution threat, the higher the attention that Airbnb entrepreneurs should pay to the pricing strategy implemented by hotels, and vice versa. Originality/value This study sheds new light on the competition threat between Airbnb and hotels. In this study, hotels and Airbnb hosts appear as two very separate markets.

scholarly journals A groupwise mutual information metric for cost efficient selection of a suitable reference in cardiac computational atlas construction

2010 ◽  
Author(s):  
Corné Hoogendoorn ◽  
Tristan Whitmarsh ◽  
Nicolas Duchateau ◽  
Federico M. Sukno ◽  
Mathieu De Craene ◽  
...  
Keyword(s):  
Mutual Information ◽  
Atlas Construction ◽  
Information Metric ◽  
Cost Efficient ◽  
Suitable Reference ◽  
Efficient Selection ◽  
Selection Of

scholarly journals Ripple Band Phase Precession of Place Cell Firing during Replay

2021 ◽  
Author(s):  
Daniel Bush ◽  
Freyja Olafsdottir ◽  
Caswell Barry ◽  
Neil Burgess
Keyword(s):  
Hippocampal Formation ◽  
Receptive Fields ◽  
Negative Relationship ◽  
Place Cell ◽  
Place Cells ◽  
Phase Coding ◽  
Equivalent Rate ◽  
Phase Precession ◽  
Cell Firing ◽  
Ripple Phase

Phase coding offers several theoretical advantages for information transmission compared to an equivalent rate code. Phase coding is shown by place cells in the rodent hippocampal formation, which fire at progressively earlier phases of the movement related 6-12Hz theta rhythm as their spatial receptive fields are traversed. Importantly, however, phase coding is independent of carrier frequency, and so we asked whether it might also be exhibited by place cells during 150-250Hz ripple band activity, when they are thought to replay information to neocortex. We demonstrate that place cells which fire multiple spikes during candidate replay events do so at progressively earlier ripple phases, and that spikes fired across all replay events exhibit a negative relationship between decoded location within the firing field and ripple phase. These results provide insights into the mechanisms underlying phase coding and place cell replay, as well as the neural code propagated to downstream neurons.

scholarly journals Combined social and spatial coding in a descending projection from the prefrontal cortex

2017 ◽  
Author(s):  
M. Murugan ◽  
M. Park ◽  
J. Taliaferro ◽  
H.J. Jang ◽  
J. Cox ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Social Behavior ◽  
Spatial Information ◽  
Spatial Association ◽  
Well Being ◽  
Unique Contribution ◽  
Social Investigation ◽  
Spatial Coding ◽  
Socially Motivated ◽  
Spatial Locations

Social interactions are crucial to the survival and well-being of all mammals, including humans. Although the prelimbic cortex (PL, part of medial prefrontal cortex) has been implicated in social behavior, it is not clear which neurons are relevant, nor how they contribute. We found that the PL contains anatomically and molecularly distinct subpopulations of neurons that target 3 downstream regions that have been implicated in social behavior: the nucleus accumbens (NAc), the amygdala, and the ventral tegmental area. Activation of NAc-projecting PL neurons (PL-NAc), but not the other subpopulations, decreased preference for a social target, suggesting an unique contribution of this population to social behavior. To determine what information PL-NAc neurons convey, we recorded selectively from them, and found that individual neurons were active during social investigation, but only in specific spatial locations. Spatially-specific inhibition of these neurons prevented the formation of a social-spatial association at the inhibited location. In contrast, spatially nonspecific inhibition did not affect social behavior. Thus, the unexpected combination of social and spatial information within the PL-NAc population appears to support socially motivated behavior by enabling the formation of social-spatial associations.

Sign in / Sign up

Export Citation Format

Share Document