RT Journal Article
SR Electronic
T1 Nanoscale dynamics of synaptic vesicle trafficking and fusion at the presynaptic active zone
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 037143
DO 10.1101/037143
A1 Thirumalini Vaithianathan
A1 Diane Henry
A1 Wendy Akmentin
A1 Gary Matthews
YR 2016
UL http://biorxiv.org/content/early/2016/02/01/037143.abstract
AB The cytomatrix at the active zone (CAZ) is a macromolecular complex that facilitates the supply of release-ready synaptic vesicles to support neurotransmitter release at synapses. To reveal the dynamics of this supply process in living synapses, we used super-resolution imaging to track single vesicles at voltage-clamped presynaptic terminals of retinal bipolar neurons, whose CAZ contains a specialized structure—the synaptic ribbon—that supports both fast, transient and slow, sustained modes of transmission. We find that the synaptic ribbon serves a dual function as a conduit for diffusion of synaptic vesicles and a platform for vesicles to fuse distal to the plasma membrane itself, via compound fusion. The combination of these functions allows the ribbon-type CAZ to achieve the continuous transmitter release required by synapses of neurons that carry tonic, graded visual signals in the retina.