Fig. 3.

Testing 3D PLA printed devices for synaptic vesicle recycling assays: (A) 3D PLA printed device (Model 003, Model 005, Model 004,Model 006) for measuring vesicle recycling activity: (B,C) vGlut1-pHlourin assay. Neurons expressing vGlut1-pHlourin are stimulated by (B) 30 mM KCl and (C) by a train of electrical pulses using GRASS S48 Stimulator. Fluorescence increases as synaptic vesicles fuse with the plasma membrane and decreases as vesicular membrane is recovered and internalised. The colour panel shows kymographic traces of each individual synapse which responds to electrical stimulus in the field of view.