Spatiotemporal bursting in simulated cultures of cortical neurons

TL;DR

Previous simulation results are extended by examining the spatiotemporal patterns of bursting behavior of developing neural networks, showing that these bursts originate at a small number of network locations and propagate as waves of activity.

Abstract

Cultures of neurons grown on multi-electrode arrays have become a common experimental preparation for investigating developing neural networks. Experiment and simulation have shown that these developing networks eventually exhibit bursting behavior in which the entire culture participates for short periods of time, with inter-burst intervals in which the network is comparatively quiescent. This paper extends previous simulation results by examining the spatiotemporal patterns of such bursting. We show that these bursts originate at a small number of network locations and propagate as waves of activity. We demonstrate that this type of activity does not require fine tuning of neuron or network parameters. We also examine how this activity changes during development and the dependence of such activity and its triggering on both local and global network properties.

Figures (6)

• Figure 1: Example of a typical whole-network burst (chosen with origin near center of network for clarity). Each image includes 10ms of activity; lighter color corresponds to larger number of spikes by that particular neuron (dark blue corresponds to no spikes). Images are 30ms apart, starting 100ms after burst initiation.
• Figure 2: Burst speed during network development for individual bursts (points) and moving average of 100 bursts (bold line) and for given $\epsilon$ (indicated at left) and $f$ (indicated above). While burst speed varies somewhat among bursts close in time, there is a clear trend.
• Figure 3: Basic burst origin sequence plots. Evolution of burst origins during development for given $\epsilon$ (indicated at left) and $f$ (indicated above). Each of the 25 subgraphs in each plot displays sequential bursts in row-major order (i.e., with first block of bursts at top left and last block at bottom right). In each subgraph, burst origin locations are indicated within the $100 \times 100$ neuron culture by black asterisks ($\ast$) with each origin connected to the next with a blue line segment. Burst counts: $(\epsilon, f) = (1.9, 0.90)$: 14,880 origins, 596 origins/subgraph (576 for last subgraph); $(\epsilon, f) = (1.9, 0.98)$: 16,815 origins, 673 origins/subgraph (663 for last subgraph); $(\epsilon, f) = (1.0, 0.90)$: 9,446 origins, 378 origins/subgraph (374 for last subgraph); $(\epsilon, f) = (1.0, 0.98)$: 9,034 origins, 362 origins/subgraph (346 for last subgraph).
• Figure 4: Burst origins histograms during development for given $\epsilon$ (indicated at left) and $f$ (indicated above). Each of the 25 subgraphs in each plot displays histograms for the corresponding subgraph from figure \ref{['fig:origin-evolution']}. All histograms tested non-uniform.
• Figure 5: Sequential correlations for burst origins during development for given $\epsilon$ (indicated at left) and $f$ (indicated above). Each of the 25 subgraphs in each plot displays $(\ell_i, \ell_{i+1})$ for the corresponding subgraph from figure \ref{['fig:origin-evolution']}.