doi:10.1016/j.biosystems.2006.05.020
Copyright © 2006 Elsevier Ireland Ltd All rights reserved.
Effect of stimulus-driven pruning on the detection of spatiotemporal patterns of activity in large neural networks
References and further reading may be available for this article. To view references and further reading you must
purchase this article.
Javier Iglesiasa, b, 
, 
and Alessandro E.P. Villaa, b, 1, ,
aInserm, U318, Laboratoire de Neurobiophysique, Université Joseph Fourier, Grenoble 1, CHU Michallon Pavillon B, BP 217, F-38043 Grenoble Cedex, France
bNeuroheuristic Research Group, Information Systems Institute, ISI, Internef, University of Lausanne, CH-1015 Lausanne, Switzerland
Received 21 December 2005;
accepted 26 May 2006.
Available online 15 November 2006.
Abstract
Adult patterns of neuronal connectivity develop from a transient embryonic template characterized by exuberant projections to both appropriate and inappropriate target regions in a process known as synaptic pruning. Trigger signals able to induce synaptic pruning could be related to dynamic functions that depend on the timing of action potentials. We stimulated locally connected random networks of spiking neurons and observed the effect of a spike-timing-dependent synaptic plasticity (stdp)-driven pruning process on the emergence of cell assemblies. The spike trains of the simulated excitatory neurons were recorded. We searched for spatiotemporal firing patterns as potential markers of the build-up of functionally organized recurrent activity associated with spatially organized connectivity.
Keywords: Preferred firing sequence; Locally connected random network; Spike-timing-dependent synaptic plasticity; Spiking neural network
Fig. 1. Example of one AB (Pr4) stimulus presentation lasting 100 ms. At each time step, dots mark the group of 40 U receiving a large excitatory input on their membrane.
Fig. 2. Graphical representation of the variables S(t), M(t) and L(t) in the STDP rule. Bold ticks mark the occurrences of spikes (S(t)=1) that correspond to the times when M(t) is reset.
Fig. 3. Outline of the general procedure followed by pattern detection algorithms: (a) analysis of a set of simultaneously recorded spike trains. Three cells, labeled A–C, participate to a patterned activity. Three occurrences of a precise pattern are detected. Each occurrence of the pattern has been labeled by a specific marker in order to help the reader to identify the corresponding spikes; (b) estimation of the statistical significance of the detected pattern; (c) display of pattern occurrences as a raster plot aligned on the pattern start.
Fig. 4. Case 1: spatiotemporal firing pattern 
formed by spikes recorded from four units: (a) differential auto-correlograms and (b) differential cross-correlograms of the four units smoothed by Gaussian shaped bin of 
width. The dotted lines represent 99% confidence limits calculated according to Abeles (1982). The average firing rates were 12.5, 18.6, 15.8, 30.3 spikes/s for units #1–4, respectively; (c) raster plot showing 33 repetitions of the pattern in the continuous pruning condition aligned on pattern start; (d) pattern occurrence timing plot: each vertical tick represents the start event of a pattern occurrence. Compare with Fig. 5 d.
Fig. 5. Case 2: spatiotemporal firing pattern 
formed by spikes recorded from one same unit. The average firing rate was 16.5 spikes/s: (a) differential auto-correlogram smoothed by Gaussian shaped bin of 5 ms; (b) raster plot showing 180 epetitions of this pattern in the interrupted pruning condition aligned on pattern start; (c) spike density histogram of the raster b smoothed by Gaussian shaped bin of 5 ms; (d) pattern occurrence timing plot: each vertical tick represents the start event of a pattern occurrence. Compare with Fig. 4 d.
Corresponding author at: Neuroheuristic Research Group, Information Systems Institute, ISI, Internef, University of Lausanne, CH-1015 Lausanne, Switzerland. Tel.: +41 21 692 35 87; fax: +41 21 692 35 85.
1 Tel.: +33 4 76 76 56 25; fax: +33 4 76 76 56 19.
Abstract
Purchase PDF (719 K)
E-mail Article
Add to my Quick Links
Cited By in Scopus (1)
Purchase PDF (236 K)
