Related Experiment Video
Updated: Aug 1, 2026

Physiological Recordings of High and Low Output NMJs on the Crayfish Leg Extensor Muscle
Published on: November 17, 2010
Multivesicular release at climbing fiber-Purkinje cell synapses
1Vollum Institute, Oregon Health Sciences University L474, 3181 S. W. Sam Jackson Park Road, Portland, OR 97201, USA.
Abstract:
Synapses driven by action potentials are thought to release transmitter in an all-or-none fashion; either one synaptic vesicle undergoes exocytosis, or there is no release. We have estimated the glutamate concentration transient at climbing fiber synapses on Purkinje cells by measuring the inhibition of excitatory postsynaptic currents (EPSCs) produced by a low-affinity competitive antagonist of AMPA receptors, gamma-DGG. The results, together with simulations using a kinetic model of the AMPA receptor, suggest that the peak glutamate concentration at this synapse is dependent on release probability but is not affected by pooling of transmitter released from neighboring synapses. We propose that the mechanism responsible for the elevated glutamate concentration at this synapse is the simultaneous release of multiple vesicles per site.
More Related Videos
12:01Acute Dissociation of Lamprey Reticulospinal Axons to Enable Recording from the Release Face Membrane of Individual Functional Presynaptic Terminals
Published on: October 1, 2014
08:31FM Dye Cycling at the Synapse: Comparing High Potassium Depolarization, Electrical and Channelrhodopsin Stimulation
Published on: May 24, 2018
Related Concept Videos
Fusion of Secretory Vesicles with the Plasma Membrane
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
Vesicular Tubular Clusters
With the help of motor proteins such...
Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Neuromuscular Junction And Blockade
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...