Spike-train responses of a pair of Hodgkin-Huxley neurons coupled by excitatory and inhibitory synapses and axons with time delay

摘要

Numerical calculations have been made on the spike-train response of a pairof Hodgkin-Huxley (HH) neurons coupled by synapses and axons with time delay.The recurrent excitatory-excitatory, inhibitory-inhibitory,excitatory-inhibitory, and inhibitory-excitatory couplings are adopted. Thecoupled, excitable HH neurons are assumed to receive the two kinds ofspike-train inputs: the transient input consisting of M impulses for the finiteduration (M: integer) and the sequential input with the constant interspikeinterval (ISI). The HH neurons in all the kinds of couplings are found to playa role of memory storage with on-off switching. When the coupling strength andthe time delay are changed, the distribution of the output ISI $T_{\rm o}$shows bifurcation (multifurcation), metastability and chaotic behavior. Thecalculation of the time correlation shows that the synchronization between thetwo HH neurons is well preserved even when the distribution of their $T_{\rmo}$ is chaotic. The correlation dimension of the cycles of $T_{\rm o}$ is shownto depend not only on the model parameters but also on the type of input ISIs.