%0 Journal Article
%T Efficient Identification of Assembly Neurons within Massively Parallel Spike Trains
%A Denise Berger
%A Christian Borgelt
%A Sebastien Louis
%A Abigail Morrison
%A Sonja Gr¨¹n
%J Computational Intelligence and Neuroscience
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/439648
%X The chance of detecting assembly activity is expected to increase if the spiking activities of large numbers of neurons are recorded simultaneously. Although such massively parallel recordings are now becoming available, methods able to analyze such data for spike correlation are still rare, as a combinatorial explosion often makes it infeasible to extend methods developed for smaller data sets. By evaluating pattern complexity distributions the existence of correlated groups can be detected, but their member neurons cannot be identified. In this contribution, we present approaches to actually identify the individual neurons involved in assemblies. Our results may complement other methods and also provide a way to reduce data sets to the ¡°relevant¡± neurons, thus allowing us to carry out a refined analysis of the detailed correlation structure due to reduced computation time. 1. Introduction Synchronized presynaptic spiking activity is known to have a higher efficacy in generating output spikes than noncoordinated spike timing [1]. Therefore, temporal coordination of spike timing is a commonly accepted signature of neuronal assembly activity [2¨C5]. Consequently, approaches to detect assembly activity have focused on the detection of correlated spiking activity on a millisecond time resolution. With massively parallel recordings becoming available at an accelerating rate [6], the likelihood of observing the signature of assembly activity is improving. However, we still lack the corresponding analysis tools [7]. Most of the existing methods are based on pairwise analysis, for example, [8¨C10]. Approaches to analyze correlations between more than two neurons exist, but typically only work for a small number of neurons [11¨C15] or only consider pairwise correlations when analyzing the assembly [16¨C19] (in these approaches a set of neurons is seen as an assembly if most of them are pairwise correlated). It is usually infeasible to simply extend existing methods that identify individual spike patterns to massively parallel data due to a combinatorial explosion. Therefore, in previous studies, we tried new approaches that evaluate the complexity distribution [20, 21] or the intersection matrix [22], which can handle massively parallel data in reasonable computational time and analyze it for higher-order spike patterns. These methods are able to detect the presence of higher-order correlation, but do not identify neurons that participate in the correlation. The goal of the present study is to resolve this issue: we want to directly identify neurons that take part
%U http://www.hindawi.com/journals/cin/2010/439648/