The Journal of Neuroscience, 2000, 20:RC50:1-5
RAPID COMMUNICATION
Synchrony Generation in Recurrent Networks with
Frequency-Dependent Synapses
Misha
Tsodyks,
Asher
Uziel, and
Henry
Markram
Department of Neurobiology, Weizmann Institute of Science, Rehovot
76100, Israel
Throughout the neocortex, groups of neurons have been found to fire
synchronously on the time scale of several milliseconds. This near
coincident firing of neurons could coordinate the multifaceted information of different features of a stimulus. The mechanisms of
generating such synchrony are not clear. We simulated the activity of a
population of excitatory and inhibitory neurons randomly interconnected
into a recurrent network via synapses that display temporal dynamics in
their transmission; surprisingly, we found a behavior of the network
where action potential activity spontaneously self-organized to produce
highly synchronous bursts involving virtually the entire network. These
population bursts were also triggered by stimuli to the network in an
all-or-none manner. We found that the particular intensities of the
external stimulus to specific neurons were crucial to evoke population
bursts. This topographic sensitivity therefore depends on the spectrum
of basal discharge rates across the population and not on the
anatomical individuality of the neurons, because this was random. These
results suggest that networks in which neurons are even randomly
interconnected via frequency-dependent synapses could exhibit a novel
form of reflex response that is sensitive to the nature of the stimulus as well as the background spontaneous activity.
Key words:
synaptic plasticity; action potential encoding; neural
network; modeling; cortical column; spike timing
Copyright © 0000 Society for Neuroscience 0270-6474/0/$05.00/0
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