Spikes Processing In Networks Of Cultured Neurons On Multi-Electrode Arrays

The detection of neural spike activity is a prerequisite for studying many types of brain function. The technology of multi-electrode arrays can stimulate and record many neurons' activities simultaneously. This technology can be used to study the function and dynamics of neural networks. A microelectrode often pick up the signals of many neurons in a local region because of the size of the microelectrode. Depending on the goals of the experiment, we wish to sort these signals by assigning particular spikes to putative neurons with some degree of reliability. The neurons' activities between different channels can be obtained by analysis of cross-correlation of spike trains in each channel.Basing on the need for studying of neural networks, I have developed SpikeTools, a visualization software programmed on MATLAB system. SpikeTools can realize spike sorting with analyzing the amplitudes, shape and principal components of the spikes and accomplish synchronous analysis of spike trains with the correlation arithmetic, which reveal the relation between neurons through the cross-correlation of spike trains between clusters or channels.The sorting result to artifical data with SpikeTools shows that over 90% of spikes are classed correctly. The sorting results to experimental data indicate that, the sorting method by amplitude can reasonably divide the spikes whose amplitudes are remarkably different; the sorting method by shape can divide the spikes based on spikes' shape whose amplitudes are contiguous; and the sorting method by principal components can distinguish the whole diversity of the wave more precisely; cluster analysis can sort spikes automatically without the manual boundary.The correlative result to experimental data indicate that a neuron is not lone when it works, and Many neurons who have relation with others can come into being a network. We can obtain the functional structure from the correlative result. So it is confered that the relation between neurons play an important role in information processing in networks.