Properties of the transmission of pulse sequences in a bistable chain of unidirectionally coupled neurons

We study the propagation of pulse sequences in a chain of neurons with sigmoidal input–output relations. The propagating speeds of pulse fronts depend on the widths of the preceding pulses and adjacent pulse fronts interact attractively. Sequences of pulse widths are then modulated through transmission. Equations for changes in pulse width sequences are derived with a kinematical model of propagating pulse fronts. The transmission of pulse width sequences in the chain is expressed as a linear system with additive noise. The gain of the system function increases exponentially with the number of neurons in a high-frequency region. The power spectrum of variations in pulse widths due to spatiotemporal noise also increases in the same manner. Further, the interaction between pulse fronts keeps the coherence and mutual information of initial and transmitted pulse sequences. Results of an experiment on an analog circuit confirm these properties.