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Updated: Aug 13, 2026
Dopamine Release at Individual Presynaptic Terminals Visualized with FFNs
Published on: August 31, 2009
The core membrane fusion complex governs the probability of synaptic vesicle fusion but not transmitter release
Michael F A Finley1, Sejal M Patel, Daniel V Madison
1Howard Hughes Medical Institute and Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, USA.
Abstract:
Synaptic vesicle fusion is driven by the formation of a four-helical bundle composed of soluble N-ethylmaleimide sensitive factor (NSF) attachment protein receptors (SNAREs). Exactly how the structural interactions that lead to the formation of this complex relate to neurotransmitter release is not well understood. To address this question, we used a strategy to "rescue" synaptic transmission after proteolytic cleavage of the synaptosome-associated protein of 25 kDa (SNAP-25) by botulinum neurotoxin E (BoNtE). Transfection of CA3 hippocampal pyramidal cells with BoNtE-resistant SNAP-25 restored synaptic transmission. Additional mutations that alter the interaction between SNAP-25 C-terminal coil and the other SNARE coils dramatically reduce transmitter release probability but leave the kinetics of synaptic responses unaltered. These data indicate that at synapses, SNARE interactions are necessary for fusion but are not the rate-limiting step of neurotransmission.
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