scholarly journals Correlated activity favors synergistic processing in local cortical networks in vitro at synaptically-relevant timescales

2019 ◽  
Author(s):  
Samantha P. Sherrill ◽  
Nicholas M. Timme ◽  
John M. Beggs ◽  
Ehren L. Newman
Keyword(s):  
Information Processing ◽  
Mutual Information ◽  
Information Transmission ◽  
Cortical Circuits ◽  
Organotypic Cultures ◽  
Neuronal Communication ◽  
Correlated Activity ◽  
The Relationship ◽  
Information Values

ABSTRACTNeural information processing is widely understood to depend on correlations in neuronal activity. However, whether correlation is favorable or not is contentious. Here, we sought to determine how correlated activity and information processing are related in cortical circuits. Using recordings of hundreds of spiking neurons in organotypic cultures of mouse neocortex, we asked whether mutual information between neurons that feed into a common third neuron increased synergistic information processing by the receiving neuron. We found that mutual information and synergistic processing were positively related at synaptic timescales (0.05-14 ms), where mutual information values were low. This effect was mediated by the increase in information transmission—of which synergistic processing is a component—that resulted as mutual information grew. However, at extrasynaptic windows (up to 3000 ms), where mutual information values were high, the relationship between mutual information and synergistic processing became negative. In this regime, greater mutual information resulted in a disproportionate increase in redundancy relative to information transmission. These results indicate that the emergence of synergistic processing from correlated activity differs according to timescale and correlation regime. In a low-correlation regime, synergistic processing increases with greater correlation, and in a high correlation regime, synergistic processing decreases with greater correlation.AUTHOR SUMMARYIn the present work, we address the question of whether correlated activity in functional networks of cortical circuits supports neural computation. To do so, we combined network analysis with information theoretic tools to analyze the spiking activity of hundreds of neurons recorded from organotypic cultures of mouse somatosensory cortex. We found that, at timescales most relevant to direct neuronal communication, neurons with more correlated activity predicted greater computation, suggesting that correlated activity does support computation in cortical circuits. Importantly, this result reversed at timescales less relevant to direct neuronal communication, where even greater correlated activity predicted decreased computation. Thus, the relationship between correlated activity and computation depends on the timescale and the degree of correlation in neuronal interactions.

scholarly journals Correlated activity favors synergistic processing in local cortical networks in vitro at synaptically relevant timescales

2020 ◽  
Vol 4 (3) ◽  
pp. 678-697
Author(s):  
Samantha P. Sherrill ◽  
Nicholas M. Timme ◽  
John M. Beggs ◽  
Ehren L. Newman
Keyword(s):  
Information Processing ◽  
Mutual Information ◽  
Information Transmission ◽  
Cortical Circuits ◽  
Correlated Activity ◽  
Neural Information ◽  
Neural Information Processing ◽  
The Relationship ◽  
Information Values

Neural information processing is widely understood to depend on correlations in neuronal activity. However, whether correlation is favorable or not is contentious. Here, we sought to determine how correlated activity and information processing are related in cortical circuits. Using recordings of hundreds of spiking neurons in organotypic cultures of mouse neocortex, we asked whether mutual information between neurons that feed into a common third neuron increased synergistic information processing by the receiving neuron. We found that mutual information and synergistic processing were positively related at synaptic timescales (0.05–14 ms), where mutual information values were low. This effect was mediated by the increase in information transmission—of which synergistic processing is a component—that resulted as mutual information grew. However, at extrasynaptic windows (up to 3,000 ms), where mutual information values were high, the relationship between mutual information and synergistic processing became negative. In this regime, greater mutual information resulted in a disproportionate increase in redundancy relative to information transmission. These results indicate that the emergence of synergistic processing from correlated activity differs according to timescale and correlation regime. In a low-correlation regime, synergistic processing increases with greater correlation, and in a high-correlation regime, synergistic processing decreases with greater correlation.

scholarly journals Synergistic neural computation is greater downstream of recurrent connectivity in organotypic cortical cultures

2020 ◽  
Author(s):  
Samantha P. Sherrill ◽  
Nicholas M. Timme ◽  
John M. Beggs ◽  
Ehren L. Newman
Keyword(s):  
Information Processing ◽  
Network Structure ◽  
Microelectrode Array ◽  
Partial Information ◽  
Neural Computation ◽  
Functional Network ◽  
Cortical Circuits ◽  
Organotypic Cultures ◽  
Local Functional ◽  
Cortical Information Processing

ABSTRACTCortical information processing requires synergistic integration of input. Understanding the determinants of synergistic integration–a form of computation–in cortical circuits is therefore a critical step in understanding the functional principles underlying cortical information processing. We established previously that synergistic integration varies directly with the strength of feedforward connectivity. What relationship recurrent and feedback connectivity have with synergistic integration remains unknown. To address this, we analyzed the spiking activity of hundreds of well-isolated neurons in organotypic cultures of mouse somatosensory cortex, recorded using a high-density 512-channel microelectrode array. We asked how empirically observed synergistic integration, quantified through partial information decomposition, varied with local functional network structure. Toward that end, local functional network structure was categorized into motifs with varying recurrent and feedback connectivity. We found that synergistic integration was elevated in motifs with greater recurrent connectivity and was decreased in motifs with greater feedback connectivity. These results indicate that the directionality of local connectivity, beyond feedforward connections, has distinct influences on neural computation. Specifically, more upstream recurrence predicts greater downstream computation, but more feedback predicts lesser computation.

scholarly journals Embedding optimization reveals long-lasting history dependence in neural spiking activity

2021 ◽  
Vol 17 (6) ◽  
pp. e1008927
Author(s):  
Lucas Rudelt ◽  
Daniel González Marx ◽  
Michael Wibral ◽  
Viola Priesemann
Keyword(s):  
Information Processing ◽  
Mutual Information ◽  
Temporal Integration ◽  
Optimization Approach ◽  
Temporal Dependence ◽  
History Dependence ◽  
Exponential Stretching ◽  
Neural Spiking ◽  
Time Lagged

Information processing can leave distinct footprints on the statistics of neural spiking. For example, efficient coding minimizes the statistical dependencies on the spiking history, while temporal integration of information may require the maintenance of information over different timescales. To investigate these footprints, we developed a novel approach to quantify history dependence within the spiking of a single neuron, using the mutual information between the entire past and current spiking. This measure captures how much past information is necessary to predict current spiking. In contrast, classical time-lagged measures of temporal dependence like the autocorrelation capture how long—potentially redundant—past information can still be read out. Strikingly, we find for model neurons that our method disentangles the strength and timescale of history dependence, whereas the two are mixed in classical approaches. When applying the method to experimental data, which are necessarily of limited size, a reliable estimation of mutual information is only possible for a coarse temporal binning of past spiking, a so-called past embedding. To still account for the vastly different spiking statistics and potentially long history dependence of living neurons, we developed an embedding-optimization approach that does not only vary the number and size, but also an exponential stretching of past bins. For extra-cellular spike recordings, we found that the strength and timescale of history dependence indeed can vary independently across experimental preparations. While hippocampus indicated strong and long history dependence, in visual cortex it was weak and short, while in vitro the history dependence was strong but short. This work enables an information-theoretic characterization of history dependence in recorded spike trains, which captures a footprint of information processing that is beyond time-lagged measures of temporal dependence. To facilitate the application of the method, we provide practical guidelines and a toolbox.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Attachment and Field Dependence: Individual Differences in Information Processing

2004 ◽  
Vol 9 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Patrizia Vermigli ◽  
Alessandro Toni
Keyword(s):  
Information Processing ◽  
Individual Differences ◽  
Field Dependence ◽  
Attachment Styles ◽  
Close Relationships ◽  
Adult Age ◽  
Males And Females ◽  
Figure Test ◽  
The Relationship ◽  
Measure Field

The present research analyzes the relationship between attachment styles at an adult age and field dependence in order to identify possible individual differences in information processing. The “Experience in Close Relationships” test of Brennan et al. was administered to a sample of 380 individuals (160 males, 220 females), while a subsample of 122 subjects was given the Embedded Figure Test to measure field dependence. Confirming the starting hypothesis, the results have shown that individuals with different attachment styles have a different way of perceiving the figure against the background. Ambivalent and avoidant individuals lie at the two extremes of the same dimension while secure individuals occupy the central part. Significant differences also emerged between males and females.

The Type of Temperament, Mood, and Strategies of Categorization

2012 ◽  
Vol 33 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Agata Wytykowska
Keyword(s):  
Information Processing ◽  
Negative Mood ◽  
Cognitive Activity ◽  
Processing Capacity ◽  
Affective Value ◽  
The Relationship ◽  
The Way

In Strelau’s theory of temperament (RTT), there are four types of temperament, differentiated according to low vs. high stimulation processing capacity and to the level of their internal harmonization. The type of temperament is considered harmonized when the constellation of all temperamental traits is internally matched to the need for stimulation, which is related to effectiveness of stimulation processing. In nonharmonized temperamental structure, an internal mismatch is observed which is linked to ineffectiveness of stimulation processing. The three studies presented here investigated the relationship between temperamental structures and the strategies of categorization. Results revealed that subjects with harmonized structures efficiently control the level of stimulation stemming from the cognitive activity, independent of the affective value of situation. The pattern of results attained for subjects with nonharmonized structures was more ambiguous: They were as good as subjects with harmonized structures at adjusting the way of information processing to their stimulation processing capacities, but they also proved to be more responsive to the affective character of stimulation (positive or negative mood).

Nonlinear Pattern Analysis of Ventricular Premature Beats by Mutual Information

1997 ◽  
Vol 36 (04/05) ◽  
pp. 257-260 ◽  
Author(s):  
H. Saitoh ◽  
T. Yokoshima ◽  
H. Kishida ◽  
H. Hayakawa ◽  
R. J. Cohen ◽  
...  
Keyword(s):  
Mutual Information ◽  
Temporal Pattern ◽  
Pattern Analysis ◽  
Autonomic Activity ◽  
Correlation Measure ◽  
Ventricular Premature Beats ◽  
Risk Of Mortality ◽  
Premature Beats ◽  
Information Values ◽  
Nonlinear Pattern

Abstract:The frequency of ventricular premature beats (VPBs) has been related to the risk of mortality. However, little is known about the temporal pattern of occurrence of VPBs and its relationship to autonomic activity. Hence, we applied a general correlation measure, mutual information, to quantify how VPBs are generated over time. We also used mutual information to determine the correlation between VPB production and heart rate in order to evaluate effects of autonomic activity on VPB production. We examined twenty subjects with more than 3000 VPBs/day and simulated ran-( dom time series of VPB occurrence. We found that mutual information values could be used to characterize quantitatively the temporal patterns of VPB generation. Our data suggest that VPB production is not random and VPBs generated with a higher value of mutual information may be more greatly affected by autonomic activity.

Plasminogen Depletion during Streptokinase Treatment or Two-Chain Urokinase Incubation Correlates with Decreased Clot Lysability Ex Vivo and In Vitro

1993 ◽  
Vol 70 (06) ◽  
pp. 0998-1004 ◽  
Author(s):  
Páll T Önundarson ◽  
H Magnús Haraldsson ◽  
Lena Bergmann ◽  
Charles W Francis ◽  
Victor J Marder
Keyword(s):  
Myocardial Infarction ◽  
Ex Vivo ◽  
Time Dependent ◽  
State Variables ◽  
Thrombolytic Treatment ◽  
Direct Proportion ◽  
Plasmin Activity ◽  
Plasma Exposure ◽  
The Relationship

SummaryThe relationship between lytic state variables and ex vivo clot lysability was investigated in blood drawn from patients during streptokinase administration for acute myocardial infarction. A lytic state was already evident after 5 min of treatment and after 20 min the plasminogen concentration had decreased to 24%, antiplasmin to 7% and fibrinogen 0.2 g/1. Lysis of radiolabeled retracted clots in the patient plasmas decreased from 37 ± 8% after 5 min to 21 ± 8% at 10 min and was significantly lower (8 ± 9%, p <0.005) in samples drawn at 20, 40 and 80 min. Clot lysability correlated positively with the plasminogen concentration (r = 0.78, p = 0.003), but not with plasmin activity. Suspension of radiolabeled clots in normal plasma pre-exposed to 250 U/ml two-chain urokinase for varying time to induce an in vitro lytic state was also associated with decreasing clot lysability in direct proportion with the duration of prior plasma exposure to urokinase. The decreased lysability correlated with the time-dependent reduction in plasminogen concentration (r = 0.88, p <0.0005). Thus, clot lysability decreases in conjunction with the development of the lytic state and the associated plasminogen depletion. The lytic state may therefore limit reperfusion during thrombolytic treatment.

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