scholarly journals A novel mutual information estimator to measure spike train correlations in a model thalamocortical network

2018 ◽  
Author(s):  
Ekaterina D. Gribkova ◽  
Baher A. Ibrahim ◽  
Daniel A. Llano
Keyword(s):  
Mutual Information ◽  
Information Transmission ◽  
Spike Train ◽  
Calcium Current ◽  
Afferent Input ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Layer 4 ◽  
The Impact ◽  
Current Conductance

AbstractThe impact of thalamic state on information transmission to the cortex remains poorly understood. This limitation exists due to the rich dynamics displayed by thalamocortical networks and because of inadequate tools to characterize those dynamics. Here, we introduce a novel estimator of mutual information and use it to determine the impact of a computational model of thalamic state on information transmission. Using several criteria, this novel estimator, which uses an adaptive partition, is shown to be superior to other mutual information estimators with uniform partitions when used to analyze simulated spike train data with different mean spike rates, as well as electrophysiological data from simultaneously recorded neurons. When applied to a thalamocortical model, the estimator revealed that thalamocortical cell T-type calcium current conductance influences mutual information between the input and output from this network. In particular, a T-type calcium current conductance of about 40 nS appears to produce maximal mutual information between the input to this network (conceptualized as afferent input to the thalamocortical cell) and the output of the network at the level of a layer 4 cortical neuron. Furthermore, at particular combinations of inputs to thalamocortical and thalamic reticular nucleus cells, thalamic cell bursting correlated strongly with recovery of mutual information between thalamic afferents and layer 4 neurons. These studies suggest that the novel mutual information estimator has advantages over previous estimators, and that thalamic reticular nucleus activity can enhance mutual information between thalamic afferents and thalamorecipient cells in the cortex.

scholarly journals A novel mutual information estimator to measure spike train correlations in a model thalamocortical network

2018 ◽  
Vol 120 (6) ◽  
pp. 2730-2744 ◽  
Author(s):  
Ekaterina D. Gribkova ◽  
Baher A. Ibrahim ◽  
Daniel A. Llano
Keyword(s):  
Mutual Information ◽  
Information Transmission ◽  
Spike Train ◽  
Calcium Current ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Sensory Signals ◽  
Layer 4 ◽  
The Impact ◽  
Current Conductance

The impact of thalamic state on information transmission to the cortex remains poorly understood. This limitation exists due to the rich dynamics displayed by thalamocortical networks and because of inadequate tools to characterize those dynamics. Here, we introduce a novel estimator of mutual information and use it to determine the impact of a computational model of thalamic state on information transmission. Using several criteria, this novel estimator, which uses an adaptive partition, is shown to be superior to other mutual information estimators with uniform partitions when used to analyze simulated spike train data with different mean spike rates, as well as electrophysiological data from simultaneously recorded neurons. When applied to a thalamocortical model, the estimator revealed that thalamocortical cell T-type calcium current conductance influences mutual information between the input and output from this network. In particular, a T-type calcium current conductance of ~40 nS appears to produce maximal mutual information between the input to this network (conceptualized as afferent input to the thalamocortical cell) and the output of the network at the level of a layer 4 cortical neuron. Furthermore, at particular combinations of inputs to thalamocortical and thalamic reticular nucleus cells, thalamic cell bursting correlated strongly with recovery of mutual information between thalamic afferents and layer 4 neurons. These studies suggest that the novel mutual information estimator has advantages over previous estimators and that thalamic reticular nucleus activity can enhance mutual information between thalamic afferents and thalamorecipient cells in the cortex. NEW & NOTEWORTHY In this study, a novel mutual information estimator was developed to analyze information flow in a model thalamocortical network. Our findings suggest that this estimator is a suitable tool for signal transmission analysis, particularly in neural circuits with disparate firing rates, and that the thalamic reticular nucleus can potentiate ascending sensory signals, while thalamic recipient cells in the cortex can recover mutual information in ascending sensory signals that is lost due to thalamic bursting.

Characterizing rare mis-sense variations of CACNA1I identified in a Swedish schizophrenia cohort

2016 ◽  
Vol 33 (S1) ◽  
pp. S182-S183
Author(s):  
J. Pan ◽  
A. Allen ◽  
L. huang ◽  
D. Daez
Keyword(s):  
Calcium Influx ◽  
Association Studies ◽  
Expression System ◽  
Single Copy ◽  
Thalamic Reticular Nucleus ◽  
Oscillatory Activity ◽  
Reticular Nucleus ◽  
Patient Specific ◽  
Genome Wide Association Studies ◽  
The Impact

CACNA1I (hCaV3.3) encodes the α1 pore-forming subunit of human voltage-gated T-type calcium channels. CaV3.3 is expressed in a limited subset of neurons including GABAergic neurons of the thalamic reticular nucleus (TRN) where they support oscillatory activity essential for sleep spindle generation. CACNA1I is implicated in schizophrenia risk by emerging genetics including genome-wide association studies (PGC, 2014), and exome sequencing of trio samples (Gulsuner et al., 2013). In order to understand the impact of disease-associated sequence variation on the function of CaV3.3, we set out to analyze a complete set of rare mis-sense coding variations in CACNA1I in a Swedish cohort, including 15 variations identified in patients, 20 identified in control subjects, and 23 in both. We established a heterologous expression system of isogenic cell lines, each carrying single-copy inducible cDNA variants of hCaV3.3, and evaluated their functional impact on channel function by electrophysiology, calcium imaging, and biochemistry. We found at least five coding variations impaired overall channel protein abundance, as well as whole cell current density. In addition, we identified hCaV3.3 variants with altered voltage-dependence of channel activation and inactivation. Overall, we found that reduced calcium influx through hCaV3.3 is associated with the group of variants identified in patients, compared to those in both patients and controls. Our findings suggest that patient-specific rare variations of CACNA1I may influence channel-dependent functions, including rebound bursting in TRN neurons, with potential implications for schizophrenia pathophysiology.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Optimal and Suboptimal Noises Enhancing Mutual Information in Threshold System

2016 ◽  
Vol 15 (02) ◽  
pp. 1650015 ◽  
Author(s):  
Qiqing Zhai ◽  
Youguo Wang
Keyword(s):  
Nonlinear System ◽  
Mutual Information ◽  
Information Transmission ◽  
Stochastic Resonance ◽  
Input Signal ◽  
Optimization Methods ◽  
Noise Distribution ◽  
The Impact

In this paper, we investigate the efficacy of noise enhancing information transmission in a threshold system. At first, in the frame of stochastic resonance (SR), optimal noise (Opt N) is derived to maximize mutual information (MI) of this nonlinear system. When input signal is discrete (binary), the optimal SR noise is found to have a finite distribution. In contrast, when input signal is continuous, the optimal SR noise is a constant one. In addition, suboptimal SR noises are explored as well with optimization methods when the types of noise added into the system are predetermined. We find that for small thresholds, suboptimal noises do not exist. Only when thresholds reach some level, do suboptimal noises come into effect. Meanwhile, we have discussed the impact of tails in noise distribution on SR effect. Finally, this paper extends the single-threshold system to an array of multi-threshold devices and presents the corresponding efficacy of information transmission produced by optimal and suboptimal SR noises. These results may be beneficial to quantization and coding.

scholarly journals GABABR Modulation of Electrical Synapses and Plasticity in the Thalamic Reticular Nucleus

2021 ◽  
Vol 22 (22) ◽  
pp. 12138
Author(s):  
Huaixing Wang ◽  
Julie S. Haas
Keyword(s):  
Signaling Pathways ◽  
Neuronal Activity ◽  
Gabab Receptor ◽  
Receptor Activation ◽  
Gabab Receptors ◽  
Electrical Synapse ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Electrical Synapses ◽  
The Impact

Two distinct types of neuronal activity result in long-term depression (LTD) of electrical synapses, with overlapping biochemical intracellular signaling pathways that link activity to synaptic strength, in electrically coupled neurons of the thalamic reticular nucleus (TRN). Because components of both signaling pathways can also be modulated by GABAB receptor activity, here we examined the impact of GABAB receptor activation on the two established inductors of LTD in electrical synapses. Recording from patched pairs of coupled rat neurons in vitro, we show that GABAB receptor inactivation itself induces a modest depression of electrical synapses and occludes LTD induction by either paired bursting or metabotropic glutamate receptor (mGluR) activation. GABAB activation also occludes LTD from either paired bursting or mGluR activation. Together, these results indicate that afferent sources of GABA, such as those from the forebrain or substantia nigra to the reticular nucleus, gate the induction of LTD from either neuronal activity or afferent glutamatergic receptor activation. These results add to a growing body of evidence that the regulation of thalamocortical transmission and sensory attention by TRN is modulated and controlled by other brain regions. Significance: We show that electrical synapse plasticity is gated by GABAB receptors in the thalamic reticular nucleus. This effect is a novel way for afferent GABAergic input from the basal ganglia to modulate thalamocortical relay and is a possible mediator of intra-TRN inhibitory effects.

A determination of excitability changes in dorsal spinocerebellar tract neurons from spike-train analysis

1977 ◽  
Vol 40 (3) ◽  
pp. 626-646 ◽  
Author(s):  
C. K. Knox ◽  
S. Kubota ◽  
R. E. Poppele
Keyword(s):  
Spike Train ◽  
Afferent Input ◽  
Complex Interactions ◽  
Group I ◽  
Long Latency ◽  
Cross Correlation Analysis ◽  
Output Spike ◽  
Type 3 ◽  
Stimulation Of

1. Responses of DSCT neurons to random electrical stimulation of peripheral nerves of the hindleg at group I intensity were studied using cross-correlation analysis of the output spike train with the stimulus. Three types of response were found: type 1 was due to monosynaptic activation of DSCT cells, type 2 resulted from inhibition of those cells, and type 3 was due to a long-latency excitation that was probably polysynaptic. 2. Most of the units studied responded to stimulation of both proximal and distal flexor and extensor nerves. The extensive convergence of afferent input on DSCT cells is much greater than has been observed previously, with type 2 and type 3 responses totaling 80% of the observed responses. We attribute this to the sensitivity of the analysis in detecting small changes in postsynaptic excitability. 3. The results of the study, particularly the derivation of postsynaptic excitability changes, generally confirm those of earlier work employing intracellular recording. 4. By varying stimulus rate and stimulus intensity in the group 1 range and simulating the resulting correlations, we conclude that excitability changes in DSCT cells are the net result of complex interactions involving excitation and inhibition. A summary of these findings is presented as a model for the minimum circuitry necessary to account for the observed behavior.

scholarly journals A Geometric Perspective on Information Plane Analysis

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 711
Author(s):  
Mina Basirat ◽  
Bernhard C. Geiger ◽  
Peter M. Roth
Keyword(s):  
Neural Network ◽  
Mutual Information ◽  
Geometric Interpretation ◽  
Neural Network Training ◽  
Neural Network Learning ◽  
Network Learning ◽  
Plane Analysis ◽  
Network Training ◽  
Hidden Layer ◽  
The Impact

Information plane analysis, describing the mutual information between the input and a hidden layer and between a hidden layer and the target over time, has recently been proposed to analyze the training of neural networks. Since the activations of a hidden layer are typically continuous-valued, this mutual information cannot be computed analytically and must thus be estimated, resulting in apparently inconsistent or even contradicting results in the literature. The goal of this paper is to demonstrate how information plane analysis can still be a valuable tool for analyzing neural network training. To this end, we complement the prevailing binning estimator for mutual information with a geometric interpretation. With this geometric interpretation in mind, we evaluate the impact of regularization and interpret phenomena such as underfitting and overfitting. In addition, we investigate neural network learning in the presence of noisy data and noisy labels.

Thalamic Reticular Nucleus in Caiman crocodilus: Immunohistochemical Staining

2018 ◽  
Vol 92 (3-4) ◽  
pp. 142-166 ◽  
Author(s):  
Michael B. Pritz
Keyword(s):  
Glutamic Acid ◽  
Glutamic Acid Decarboxylase ◽  
Immunohistochemical Staining ◽  
Medial Forebrain Bundle ◽  
Transverse Plane ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Acid Decarboxylase ◽  
Caiman Crocodilus ◽  
Monoclonal Mouse

The thalamic reticular nucleus in reptiles, Caiman crocodilus, shares a number of morphological similarities with its counterpart in mammals. In view of the immunohistochemical properties of this nucleus in mammals and the more recently identified complexity of this neuronal aggregate in Caiman, this nucleus was investigated using a number of antibodies. These results were compared with findings described for other amniotes. The following antibodies gave consistent and reproducible results: polyclonal sheep anti-parvalbumin (PV), monoclonal mouse anti-PV, and polyclonal sheep anti-glutamic acid decarboxylase (GAD). In the transverse plane, this nucleus is divided into two. In each part, a compact group of cells sits on top of the fibers of the forebrain bundle with scattered cells among these fibers. In the lateral forebrain bundle, this neuronal aggregate is represented by the dorsal peduncular nucleus and the perireticular nucleus while, in the medial forebrain bundle, these parts are the interstitial nucleus and the scattered cells in this fiber tract. The results of this study are the following. First, the thalamic reticular nucleus of Caiman contains GAD(+) and PV(+) neurons, which is similar to what has been described in other amniotes. Second, the morphology and distribution of many GAD(+) and PV(+) neurons in the dorsal peduncular and perireticular nuclei are similar and suggest that these neurons colocalize these markers. Third, neurons in the interstitial nucleus and in the medial forebrain bundle are GAD(+) and PV(+). At the caudal pole of the thalamic reticular nucleus, PV immunoreactive cells predominated and avoided the central portion of this nucleus where GAD(+) cells were preferentially located. However, GAD(+) cells were sparse when compared with PV(+) cells. This immunohistochemically different area in the caudal pole is considered to be an area separate from the thalamic reticular nucleus.

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