Mathematical Biosciences and Engineering (MBE)

Integrator or coincidence detector --- what shapes the relation of stimulus synchrony and the operational mode of a neuron?

Pages: 521 - 535, Volume 13, Issue 3, June 2016      doi:10.3934/mbe.2016005

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Achilleas Koutsou - Department of Computer Science, University of Cyprus, 1678 Nicosia, Cyprus (email)
Jacob Kanev - Department of Electrical Engineering and Computer Science, Technische Universitat Berlin, 10587 Berlin, Germany (email)
Maria Economidou - Department of Computer Science, University of Cyprus, 1678 Nicosia, Cyprus (email)
Chris Christodoulou - Department of Computer Science, University of Cyprus, 1678 Nicosia, Cyprus (email)

Abstract: The operational mode of a neuron (i.e., whether a neuron is an integrator or a coincidence detector) is in part determined by the degree of synchrony in the firing of its pre-synaptic neural population. More specifically, it is determined by the degree of synchrony that causes the neuron to fire. In this paper, we investigate the relationship between the input and the operational mode. We compare the response-relevant input synchrony, which measures the operational mode and can be determined using a membrane potential slope-based measure [7], with the spike time distance of the spike trains driving the neuron, which measures spike train synchrony and can be determined using the multivariate SPIKE-distance metric [10]. We discover that the relationship between the two measures changes substantially based on the values of the parameters of the input (firing rate and number of spike trains) and the parameters of the post-synaptic neuron (synaptic weight, membrane leak time constant and spike threshold). More importantly, we determine how the parameters interact to shape the synchrony-operational mode relationship. Our results indicate that the amount of depolarisation caused by a highly synchronous volley of input spikes, is the most influential factor in defining the relationship between input synchrony and operational mode. This is defined by the number of input spikes and the membrane potential depolarisation caused per spike, compared to the spike threshold.

Keywords:  Operational mode, membrane potential slope, input synchrony, spike distance metrics, coincidence detection, temporal integration.
Mathematics Subject Classification:  92B25, 92C20, 92-08.

Received: March 2015;      Accepted: November 2015;      Available Online: January 2016.