Title
Membrane Properties And The Balance Between Excitation And Inhibition Control Gamma-Frequency Oscillations Arising From Feedback Inhibition
Abstract
Computational studies as well as in vivo and in vitro results have shown that many cortical neurons fire in a highly irregular manner and at low average firing rates. These patterns seem to persist even when highly rhythmic signals are recorded by local field potential electrodes or other methods that quantify the summed behavior of a local population. Models of the 30-80 Hz gamma rhythm in which network oscillations arise through 'stochastic synchrony' capture the variability observed in the spike output of single cells while preserving network-level organization. We extend upon these results by constructing model networks constrained by experimental measurements and using them to probe the effect of biophysical parameters on network-level activity. We find in simulations that gamma-frequency oscillations are enabled by a high level of incoherent synaptic conductance input, similar to the barrage of noisy synaptic input that cortical neurons have been shown to receive in vivo. This incoherent synaptic input increases the emergent network frequency by shortening the time scale of the membrane in excitatory neurons and by reducing the temporal separation between excitation and inhibition due to decreased spike latency in inhibitory neurons. These mechanisms are demonstrated in simulations and in vitro current-clamp and dynamic-clamp experiments. Simulation results further indicate that the membrane potential noise amplitude has a large impact on network frequency and that the balance between excitatory and inhibitory currents controls network stability and sensitivity to external inputs.
Year
DOI
Venue
2012
10.1371/journal.pcbi.1002354
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
membrane potential,action potentials,local field potential,population model,oscillations,computer simulation
Population,Synapse,Membrane potential,Biology,Biological system,Excitatory postsynaptic potential,Inhibitory postsynaptic potential,Local field potential,Gamma Rhythm,Genetics,Patch clamp
Journal
Volume
Issue
ISSN
8
1
1553-7358
Citations 
PageRank 
References 
4
0.44
10
Authors
2
Name
Order
Citations
PageRank
Michael N. Economo1131.50
John A. White226641.37