Stability and Flexibility of Small Neural Circuits (CPGs)

Overview

How can oscillatory neural circuits generate spatio-temporal activity patterns that are robust in the presence of noise yet flexible enough to provide specific, reproducible, adaptive responses to inputs? This problem is central to sensory processing as well as motor coordination. Our approach to this question involves a well-established and productive, interdisciplinary team from Biology, Physics and Nonlinear Dynamics. It combines nonlinear dynamical analysis, computational and electronic modeling, and neurophysiological studies of a tractable, oscillatory motor circuit from the crustacean stomatogastric system. Using these approaches, we search for the origin of robustness and flexibility at 3 levels of organization: the individual neuron, subcircuits of identified neurons and small microcircuits made up of identified neurons and synapses. Each level is studied using neurophysiological, modeling and dynamical analytical techniques. To validate our computations, we use dynamical neuron models, implemented in hardware and operating in real time, as substitutes for biological neurons in real neural circuits, and as components of simulated networks.

Dynamics of individual neurons. Here and in the other projects, we probe robustness by the response to stochastic signals, flexibility by responses to deterministic inputs.

Cooperative dynamics in subcircuits. Using natural or simulated synapses, we connect real and/or artificial neurons in small microcircuits. We ask two principal questions: How can neurons operating with complex, variable dynamics interact synaptically to generate stable yet flexible rhythms

Robustness and flexibility in highly interconnected microcircuits. Using the pyloric and gastric CPG and model circuits, we test the functional role of heterogenous neuronal dynamics, synaptic properties, redundancy and multiple interconnections.

People

Publications

A. Szûcs, R. D. Pinto, M. I. Rabinovich, H. D. I. Abarbanel, A. I. Selverston (2003). Synaptic modulation of the interspike interval signatures of bursting pyloric neurons.
J Neurophysiol 89(3): 1363-77 (2003)

Szücs A, Elson RC, Rabinovich MI, Abarbanel HD, Selverston AI. Nonlinear behavior of sinusoidally forced pyloric pacemaker neurons.
J Neurophysiol. 85(4):1623-38 (2001)

Pinto RD, Elson RC, Szücs A, Rabinovich MI, Selverston AI, Abarbanel HD. Extended dynamic clamp: controlling up to four neurons using a single desktop computer and interface.
J Neurosci Methods. 108(1):39-48 (2001)

Elson RC, Selverston AI, Abarbanel HD, Rabinovich MI. Inhibitory synchronization of bursting in biological neurons: dependence on synaptic time constant.
J Neurophysiol. 88(3):1166-76 (2002)

P. Varona, J.J. Torres, R. Huerta, H.D.I. Abarbanel, M.I. Rabinovich Regularization mechanisms of spiking-bursting neurons
Neural Networks, 14: 865-875 (2001)

F.B. Rodríguez, P. Varona, R. Huerta, M.I. Rabinovich, H.D.I. Abarbanel Richer network dynamics of intrinsically non-regular neurons measured through mutual information
Lect. Notes Comput. Sc., 2084:490-497 (2001)

M.I. Rabinovich, P. Varona, H.D.I. Abarbanel Nonlinear Cooperative Dynamics of Living Neurons
International Journal of Bifurcation and Chaos 10 (5): 913-933 (2000)

M.I. Rabinovich, P. Varona, J.J. Torres, R. Huerta, H.D.I. Abarbanel Slow dynamics and regularization phenomena in ensembles of chaotic neurons
Physica  A, 263:405-414 (1999)

P. Varona, J. J. Torres, H. D. I. Abarbanel, M. I. Rabinovich, and R. Elson Dynamics of Two Electrically Coupled Chaotic Neurons: Experimental Observations and Model Analysis
Biological Cybernetics, 84(2):91-101 (2001)

R. Huerta, P. Varona, M. I. Rabinovich, H.D.I. Abarbanel. Topology selection by chaotic neurons of a pyloric central pattern generator,
Biological Cybernetics 84, L1-L8 (2001)

A. I. Selverston, M. I. Rabinovich, H. D. I. Abarbanel, R. Elson, A. Szücs, R. Pinto, R. Huerta, P. Varona. Reliable circuits from irregular neurons: a dynamical approach to understanding central pattern generators
J. Physiology 94357-374 (2000)

M. Falcke, R. Huerta, M. I. Rabinovich, Henry D. I. Abarbanel, Robert C. Elson, Allen I. Selverston. Modeling Observed Chaotic Oscillations in Bursting Neurons: The Role of Calcium Dynamics and IP3.
Biological Cybernetics 82:517-527 (2000)

Szücs A, Varona P, Volkovskii AR, Abarbanel HD, Rabinovich MI, Selverston AI. Interacting biological and electronic neurons generate realistic oscillatory rhythms.
Neuroreport. 11(3):563-9 (2000)

R. Huerta, M. A. Sánchez-Montañés, F. Corbacho, J. A. Sigüenza. A central pattern generator to control a pyloric-based system,
Biological Cybernetics 82:85 (2000)

Selverston A. What invertebrate circuits have taught us about the brain.
Brain Res Bull. 50(5-6):439-40 (1999)

R. C. Elson, R. Huerta, Rabinovich M, Abarbanel, A. I. Selverston, Dynamic Control of Irregular Bursting in an Identified Neuron of an Oscillatory Circuit
Journal of Neurophysiology 82(1):115-122 (1999)

Selverston A. General principles of rhythmic motor pattern generation derived from invertebrate CPGs.
Prog Brain Res. 123:247-57 (1999)

Selverston A, Elson R, Rabinovich M, Huerta R, Abarbanel H, Basic principles for generating motor output in the stomatogastric ganglion,
Ann N Y Acad Sci 860:35-50 (1998)

R. C. Elson, A. I. Selverston, R. Huerta, N. F. Rulkov, M. I. Rabinovich and H. D. I. Abarbanel, Synchronous Behavior of Two Coupled biological Neurons,
Physical Review Letters 81(25):5692 (1998)

M. I. Rabinovich, H. D. I. Abarbanel, R. Huerta, R. Elson, y A. Selverston, Self-regularization of Chaos in Neural Systems: Experimental and Theoretical Results.
IEEE Transactions on Circuits and Systems 44 (10):997-1005 (1997)

M. I. Rabinovich, A. Selverston, L. L. Rubchinsky and R. Huerta. Dynamics and kinematics of simple neural systems.
Chaos 6(3):288 (1996)

H. D. I. Abarbanel, M.I. Rabinovich, A. Selverston, M.V.Bazhenov, R.Huerta, L.L. Rubchinsky, and M.M.Sushchik, The synchronization of Neural Assemblies,
Uspekhi Fizicheskih Nauk 166(4):1-28 (1996)

H. D. I. Abarbanel, R. Huerta, M. I. Rabinovich, N. F. Rulkov, P. F. Rowat and A. Selverston, Synchronized Action of Synaptically Coupled Chaotic Model Neurons,
Neural Computation 8(8):1567-1602 (1996)