Evidence for Chaos in Spike Trains of Neurons That Generate Rhythmic Motor Patterns

摘要

The findings presented here of work on the opisthobranch mollusc Pleurobranchaea californica indicate that some of the variability that has been observed in the activity of neurons during patterned motor activity may be attributable to low-dimensional chaos. We obtained long trains of action potentials (spikes) from these neurons, scanned them using adjacent temporal windows having equal widths, and converted the counts into frequency times series. The present findings are similar to those of previous work in which equal-interval time series were obtained by interpolation of the unequal-interval spike trains. We discuss the implications of chaos and the difficulties in the application of extant dynamical tools to spike trains. An accompanying paper inquires into the ability of neural networks to read and transmit chaotic activity. Keywords: Chaos; Fractals; Mollusc; Motor systems; Parallel processing; Self-organization; Neurochemistry; Nerve transmission; Nerve impulses; Reprints. (KT)