RAPID STATE SWITCHING IN BALANCED CORTICAL NETWORK MODELS

We have explored a network model of cortical microcircuits based on integrate-and-fire neurons in a regime where the reset following a spike is small, recurrent excitation is balanced by feedback inhibition, and the activity is highly irregular. This regime cannot be described by a mean-field theory based on average activity levels because essential features of the model depend on fluctuations from the average. We propose a new way of scaling the strength of synaptic interaction with the size of the network: rather than scale the amplitude of the synapse we scale the neurotransmitter release probabilities with the number of inputs to keep the average input constant. This is consistent with the low transmitter release probability observed in a majority of hippocampal synapses. Another prominent feature of this regime is the ability of the network to switch rapidly between different states, as demonstrated in a model based on an orientation columns in the mammalian visual cortex. Both network and intrinsic ...

[1]  D. R. Smith,et al.  A STATISTICAL ANALYSIS OF THE CONTINUAL ACTIVITY OF SINGLE CORTICAL NEURONES IN THE CAT UNANAESTHETIZED ISOLATED FOREBRAIN. , 1965, Biophysical journal.

[2]  I. Ohzawa,et al.  The effects of contrast on visual orientation and spatial frequency discrimination: a comparison of single cells and behavior. , 1987, Journal of neurophysiology.

[3]  H. Sompolinsky,et al.  Theory of orientation tuning in visual cortex. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[4]  J. Cowan,et al.  Excitatory and inhibitory interactions in localized populations of model neurons. , 1972, Biophysical journal.

[5]  Abbott,et al.  Asynchronous states in networks of pulse-coupled oscillators. , 1993, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[6]  D. Ferster.  Orientation selectivity of synaptic potentials in neurons of cat primary visual cortex , 1986, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[7]  B. Mandelbrot,et al.  RANDOM WALK MODELS FOR THE SPIKE ACTIVITY OF A SINGLE NEURON. , 1964, Biophysical journal.

[8]  Daniel J. Amit,et al.  E ective neurons and attractor neural networks in cortical environment , 1992 .

[9]  B. Sakmann,et al.  Fast and slow components of unitary EPSCs on stellate cells elicited by focal stimulation in slices of rat visual cortex. , 1992, The Journal of physiology.

[10]  J. T. Massey,et al.  Mental rotation of the neuronal population vector. , 1989, Science.

[11]  Christian Rosenmund,et al.  Nonuniform probability of glutamate release at a hippocampal synapse. , 1993, Science.

[12]  R. Malinow,et al.  The probability of transmitter release at a mammalian central synapse , 1993, Nature.

[13]  S. Nelson,et al.  An emergent model of orientation selectivity in cat visual cortical simple cells , 1995, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[14]  William R. Softky,et al.  The highly irregular firing of cortical cells is inconsistent with temporal integration of random EPSPs , 1993, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[15]  Daniel J Amittt.  Effective neurons and attractor neural networks in cortical environment , 1992 .

[16]  A. Georgopoulos,et al.  Cognitive neurophysiology of the motor cortex. , 1993, Science.

[17]  D. Hubel,et al.  Receptive fields and functional architecture of monkey striate cortex , 1968, The Journal of physiology.

[18]  R. Douglas,et al.  A functional microcircuit for cat visual cortex. , 1991, The Journal of physiology.

[19]  Daniel J. Amit,et al.  Quantitative Study of Attractor Neural Network Retrieving at Low Spike Rates: I , 1991 .

[20]  D. Whitteridge,et al.  An intracellular analysis of the visual responses of neurones in cat visual cortex. , 1991, The Journal of physiology.

[21]  A. Treves.  Mean-field analysis of neuronal spike dynamics , 1993 .

[22]  S. Thorpe,et al.  Dynamics of orientation coding in area V1 of the awake primate , 1993, Visual Neuroscience.

[23]  M. Tovée,et al.  Information encoding and the responses of single neurons in the primate temporal visual cortex. , 1993, Journal of neurophysiology.

[24]  J. Deuchars,et al.  Temporal and spatial properties of local circuits in neocortex , 1994, Trends in Neurosciences.

[25]  Michael N. Shadlen,et al.  Noise, neural codes and cortical organization , 1994, Current Opinion in Neurobiology.

[26]  Daniel J. Amit,et al.  Attractor neural networks with biological probe records , 1990 .