Numerical simulation of a classic integrate-and-fire neuron model, driven by a periodic spike train and a Poisson noise train, demonstrates for the first time that stochastic resonance is a property that is available in neural transmission of spike trains. Beyond peripheral sensory neurons that process analog stimuli, our study extends to central neurons that process spike trains, the possibility of noise-enhanced signal transmission. Also, it enlarges the scope of stochastic resonance to the transmission of signals formed by trains of discrete pulses.