Among the most easily recognizable features of any nervous system is the synapse. While the question of how synapses evolved has been a longstanding mystery, it can now largely be solved. In a nutshell, it appears that the synapses between neurons evolved directly from the original cell-to-cell contacts, namely, the adherence junctions and other bonds that linked the primitive epithelial sheets of early multicellular organisms.
Click here for original story, The evolution of the synapse
Source: Phys.org