Coherent Behavior in Neuronal Networks (eBook)

Coherent Behaviorin Neuronal Networks 5
On the Dynamics of Synaptic Inputs During Ongoing Activity in the Cortex 12
Introduction 12
Synchrony in Spontaneous Activity 15
Excitation and Inhibition During Spontaneous Activity 16
Repeating Patterns in the Spontaneous Subthreshold Membrane Potential Fluctuations of Cortical Neurons 19
Conclusions 24
References 25
Timing Excitation and Inhibition in the Cortical Network 28
Excitation and Inhibition During Cortical Up and Down States 28
Experimental Procedures and Detection of Synaptic Events 32
Intracellular and Extracellular Recordings In Vitro and In Vivo 32
Data Analysis 33
A Short Discussion on the Method 33
Experimental Results 35
Excitatory and Inhibitory Events During Risetime of Up States In Vitro 37
Excitatory and Inhibitory Events During the End of Up States In Vitro 39
Excitatory and Inhibitory Events During Risetime of Up States In Vivo 41
Excitatory and Inhibitory Events During the End of Up States In Vivo 42
Excitation and Inhibition in Up and Down states Generated in a Cortical Model 43
Modeling the Cortex 44
Excitatory and Inhibitory Events During Up States In Computo 46
Timing of Excitation and Inhibition in Cortical Activity 49
Appendix 53
Intracellular and Population Recordings In Vitro and In Vivo 53
In Vitro Recordings 53
In Vivo Recordings 53
Recordings and Stimulation 53
Data Analysis and Detection of Synaptic Events 54
References 54
Finding Repeating Synaptic Inputs in a Single Neocortical Neuron 58
Introduction 58
Repeat Detection 59
Significance Testing 63
Implanted, Artificial Repeats 65
An Improved Repeat Detector 65
Recording Conditions and Effects on Synaptic Repeat Detection 68
References 70
Reverberatory Activity in Neuronal Networks 72
Background 72
Reverberatory Activity in Cultured Neuronal Networks 74
Biophysical Mechanisms Underlying Persistent In Vitro Reverberation 77
Intrinsic Bistability vs. Recurrent Excitation 77
Asynchronous Synaptic Transmission 78
Short-Term Synaptic Dynamics 81
Summary and Outlook 82
References 83
Gap Junctions and Emergent Rhythms 87
Introduction 87
The Absolute Integrate-and-Fire Model 89
Spike Adaptation 90
Phase Response Curve 93
Gap-Junction Coupling 94
Existence of the Asynchronous State 95
Stability of the Asynchronous State 96
Discussion 101
References 102
The Feed-Forward Chain as a Filter-Amplifier Motif 105
Introduction 105
Synchrony-Breaking Hopf Bifurcations 108
Periodic Forcing of Feed-Forward Chains 110
Simulations 111
Experiments 114
Periodic Forcing near Hopf Bifurcation 115
Simulations 116
Asymmetry and Multiplicity in Response Curve 116
Scalings of Solution Amplitudes 121
Q-Factor 125
Cochlear Modeling 127
Hopf Models of the Auditory System 127
Two-Frequency Forcing 128
References 129
Gain Modulation as a Mechanism for Switching Reference Frames, Tasks, and Targets 131
The Problem of Behavioral Flexibility 131
What is Gain Modulation? 132
Experimental Evidence for Gain Modulation 134
Modulation by Proprioceptive Information 134
Attentional Modulation 135
Nonlinear Interactions between Multiple Stimuli 135
Context- and Task-Dependent Modulation 136
Computations Based on Gain Modulation 137
Coordinate Transformations 138
Arbitrary Sensory-Motor Remapping 142
How the Contextual Switch Works 143
Switching as a Fundamental Operation 145
Flexible Responses to Complex Stimuli 148
References 150
Far in Space and Yet in Synchrony: Neuronal Mechanisms for Zero-Lag Long-Range Synchronization 153
Introduction 153
How can Zero-Lag Long-Range Synchrony Emerge Despite of Conduction Delays? 155
Zero-Lag Long-Range Neuronal Synchrony via Dynamical Relaying 158
Illustration of Dynamical Relaying in a Module of Three HH Cells 158
Effect of a Broad Distribution of Conduction Delays 161
Dynamical Relaying in Large-Scale Neuronal Networks 163
General Discussion, Conclusions and Perspectives 167
Methods 170
Models 170
Simulations 173
Data Analysis 173
References 174
Characterizing Oscillatory Cortical Networks with Granger Causality 178
Introduction 178
Granger Causality Analysis 179
Estimation of Autoregressive Models 184
Numerical Simulations 186
Laminar Organization of the Cortical Alpha Rhythm 190
The Choice of Neural Signals for Neuronal Interaction Analysis 195
Summary 197
References 197
Neurophysiology of Interceptive Behavior in the Primate: Encoding and Decoding Target Parameters in the Parietofrontal System 199
Introduction 199
Behavioral Aspects of an Interceptive Action 200
Visual Motion Processing 201
The Interception Task 202
Sensorimotor Processing During the Interception of Circularly Moving Targets 202
Encoding of Angular Position and Time-to-Contact During the Interception Task 204
Decoding of Angular Position and Tau During Interception of Circularly Moving Targets 208
Concluding Remarks 212
References 213
Noise Correlations and Information Encoding and Decoding 215
Introduction 215
Defining Noise Correlations 216
Theoretical Studies: Noise Correlations and Information Encoding 218
Theoretical Studies: Noise Correlations and Information Decoding 220
Empirical Studies: Noise Correlations and Information Encoding and Decoding 220
Theoretical Analysis of the Effects of Correlations on Encoding and Decoding in Pairs 221
Empirical Validation 224
Effects of Noise Correlations on Information Encoding and Decoding 229
Population Effects of Noise Correlations 230
Conclusion 235
References 235
Stochastic Synchrony in the Olfactory Bulb 1
Basic Circuitry of the Olfactory Bulb Mediates Recurrent and Lateral Inhibition 238
Slow Kinetics of Lateral Inhibition are Incompatible with Synchronization of Fast Oscillations 238
Gamma Oscillations are Intrinsic to Olfactory Bulb and to Mitral Cells 239
Mitral Cells are Oscillators with a Preferred Frequency of 40Hz 239
Noise-Induced Oscillatory Synchrony 240
Stochastic Synchrony 241
Phase Reduction and Lyapunov Exponents 243
Noise Color and Reliability 246
Input/Output Correlations 249
Summary 250
References 250
Stochastic Neural Dynamics as a Principle of Perception 254
Introduction 254
Brain Dynamics: From Spiking Neurons to Reduced Rate-Models 255
Perceptual Detection and Stochastic Dynamics 258
Neurophysiology 258
A Computational Model of Probabilistic Detection 263
References 268
Large-Scale Computational Modeling of the Primary Visual Cortex 270
Introduction 270
Physiological Background 275
The Large-Scale Computational Model 278
Dynamics of the Primary Visual Cortex 281
Patterns of Spontaneous Cortical Activity 282
Line-Motion Illusion 288
Orientation Tuning 293
Discussion 297
References 298
Index 304