Formation of apparent presynaptic elements in response to poly-basic compounds.

Neuronal cell processes in dispersed cell culture grow out onto Sepharose beads coated with poly-basic proteins. Apparent presynaptic elements are formed by these neuronal processes with the bead serving as a postsynaptic element. It is suggested that electrostatic binding between poly-acidic groups on the presynaptic element and poly-basic troups on the postsynaptic element is one of the initial steps in the formation of a synaptic contact in culture.