Prof. Jürgen Klingauf "Xenapses: pure presynaptic structures induced by direct neuronal Interfacing on functionalized microstructured coverslips"

Using click-chemistry we functionalized micropatterned coverglasses with protein domains of synaptic cell adhesion molecules, serving as artificial postsynapses. On these host substrates purely presynaptic
boutons form `en face´ directly onto the coverslip, termed `xenapses´. Serial section TEM as well as focused-ion-beam SEM showed that xenapses contain a few hundred synaptic vesicles), many of them docked in
several clusters at the bottom membrane. 4Pi and TIRF-STORM confirmed the existence of several active zones. Thus, xenapses offer the unique opportunity to record exocytosis of single vesicles by TIRFM. Using fusion constructs of the pH-sensitive pHluorin, single fusion events were visible as diffraction-limited spots on stimulation with single action potentials. We could localize fusion events synchronous to action potentials with ~20 nm precision and follow the fate of released synaptic vesicle proteins. This novel hemisynapse culture system could open up new avenues not only for basic synaptic research, but also for clinical applications.

invited by Prof. Jan C. Behrends