Distant neuronal populations are observed to synchronize their activity patterns at zero-lag during certain stages of cognitive acts. This chapter provides an overview of the problem of large-scale synchrony and some of the solutions that have been proposed for attaining long-range coherence in the nervous system despite long conduction delays. We also review in detail the synchronizing properties of a canonical neuronal micro-circuit that naturally enhances the isochronous discharge of remote neuronal resources. The basic idea behind this mechanism is that when two neuronal populations relay their activities onto a third mediating population, the redistribution of the dynamics performed by the latter leads to a selforganized and lag-free synchronization among the pools of neurons being relayed. Exploring the physiological relevance of this mechanism, we discuss the role of associative thalamic nuclei and its bidirectional interaction with the neocortex as a relevant physiological structure in which the network module under study is densely embedded. These results are further supported by the recently proposed role of thalamocortical interactions as a substrate for the trans-areal cortical coordination.