Firing and signal transduction associated with an intrinsic oscillation in neuronal systems

We study the nonlinear firing and signal transduction of a neuron subject to both a constant stimulus and a weak periodic signal, each of which is too small to, separately, fire spikes for the neuron. The subthreshold constant stimulus, regarded as the total input to the neuron from other neurons and from the external world, is found to give rise to only an intrinsic subthreshold oscillation. This oscillation can lead to the transduction of the weak periodic signal via a mechanism similar to stochastic resonance. This may enable us to understand reported experimental results of oscillation associated signal transduction and of finite signal-to-noise ratio in the absence of external noise. In addition, the most sensitive frequency range for signal transduction is also found.