Neuroligin-1-Modified Electrodes for Specific Coupling with a Presynaptic Neuronal Membrane

Abstract

Coordination of synapses onto electrodes with high specificity and maintaining a stable and long-lasting interface have importance in the field of neural interfaces. One potential approach is to present ligands on the surface of electrodes that would be bound through a protein-protein interaction to specific areas of neuronal cells. Here, we functionalize electrode surfaces with genetically engineered neuroligin-1 protein and demonstrate the formation of a nascent presynaptic bouton upon binding to neurexin-1 β on the presynaptic membrane of neurons. The resulting synaptically connected electrode shows an assembly of presynaptic proteins and comparable exocytosis kinetics to that of native synapses. Importantly, a neuroligin-1-induced synapse-electrode interface exhibits type specificity and structural robustness. We envision that the use of synaptic adhesion proteins in modified neural electrodes may lead to new approaches in the interfacing of neural circuity and electronics.

Keywords: induced synapse; neural interface; neuroligin−neurexin interaction; presynaptic differentiation; primary cultured neuron; surface modification.