  We present a new interpretation for encoding information of the period of
input signals into spike-trains in individual sensory neuronal systems. The
spike-train could be described as the waveform sample of the input signal which
locks sample points to wave crests with randomness. Based on simulations of the
Hodgkin-Huxley (HH) neuron responding to periodic inputs, we demonstrate that
the random sampling is a proper encoding method in medium frequency region
since power spectra of the reconstructed spike-trains are identical to that of
neural signals.
