Summary: Journal of Computational Neuroscience, 1, 313-321 (1994)
9 1994 Kluwer Academic Publishers, Boston. Manufactured in The Netherlands.
When Inhibition not Excitation Synchronizes Neural Firing
CARL VAN VREESWIJK AND L.F. ABBOTT
Centerfor Complex Systems, Brandeis University, Waltham, MA 02254
G. BARD ERMENTROUT
Department of Mathematics, University of Pittsburgh, Pittsburgh, PA 15260
Received April 13, 1994; Revised July 22, 1994; Accepted(in revisedform)July 27, 1994.
Action Editor: J. Rinzel
Abstract. Excitatory and inhibitory synaptic coupling can have counter-intuitive effects on the synchroniza-
tion of neuronal firing. While it might appear that excitatory coupling would lead to synchronization, we show
that frequently inhibition rather than excitation synchronizes firing. We study two identical neurons described
by integrate-and-fire models, general phase-coupled models or the Hodgkin-Huxley model with mutual, non-
instantaneous excitatory or inhibitory synapses between them. We find that if the rise time of the synapse is longer
than the duration of an action potential, inhibition not excitation leads to synchronized firing.
It is commonly assumed that excitatory synaptic cou-
pling tends to synchronize neural firing while inhibitory
coupling pushes neurons toward anti-synchrony. Such
behavior has been seen in models of neuronal cir-