Shuichi Doi

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A neuron can respond to periodic inhibitory input with a variety of complex behaviors, periodic and aperiodic. We present a succession of models to test hypotheses for mechanisms underlying complex behavior generation. Model comparison using non-linear dynamics techniques indicates that long-duration IPSP aftereffects and spiking behavior are necessary for(More)
The characteristics of the BVP neuron model response to periodic pulse stimuli are investigated. Temporal patterns of the output of the model are analyzed as a function of the stimulus intensity and period. The BVP model exhibits the same chaotic behavior, and a Cantor function-like graph of the response frequency (mean firing rate) as in(More)
A simple mathematical model of living pacemaker neurons is proposed. The model has a unit circle limit cycle and radial isochrons, and the state point moves slowly in one region and fast in the remaining region; regions can correspond to the subthreshold activity and to the action potentials of pacemaker neurons, respectively. The global bifurcation(More)
The response characteristics of the BVP (Bonhoeffer-van der Pol or FitzHugh-Nagumo) neuronal model to periodic pulse trains were investigated. The global bifurcation structure of model relative to stimulus intensity and period were analyzed using a one-dimensional mapping called the phase transition curve (PTC) extended by Maginu. The PTC clarified how(More)
We found that decayed wood stakes with no termite damage collected from a termite-infested field exhibited a deterrent effect against the termite Reticulitermes speratus, Kolbe, 1885. The effect was observed to be lost or reduced by drying. After identification, it was found that the decayed stakes were infected by brown rot fungus Fibroporia radiculosa(More)
A method for identification and typing of wood rotting fungi using the melting temperature [T(m)] of DNA fragments coding rRNA (rDNA) was examined. The T(m)s of four DNA fragments, inter transcribed spacer (ITS) I, ITS II, and two partial fragments of 28S rDNA from each of 20 species of wood rotting fungi, were measured by melting curve analysis. The T(m)(More)
The main feature separating a living pacemaker from other oscillators is the fact that the former has not only the oscillatory property but also slow and fast changes of the membrane potential corresponding to the sub- and suprathreshold regions. We propose a simple mathematical model called mRIC and show that the model exhibited the essential feature of(More)
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