At the beginning I discuss the different forms of synchrony as a specific dynamical relationship between neurons in the experiments and models. The main question is: How does postsynaptic neuron respond to a periodic spike train in its input? The new results that I am going to present are related to the cooperative dynamics of two unidirectional coupled H-H neurons with synapse that follows the rules of Spike-Time Dependent Plasticity (learning). This plasticity of the coupling between neurons produces enlarged frequency and phase locking zones and results in synchronization that is more rapid and much more robust against synaptic noise than synchronization with "non-plastic" synapse.