When the presynaptic membrane is stimulated by the influx of calcium ions, it releases a chemical called a neurotransmitter, which travels over the synaptic cleft in order to bind to the postsynaptic membrane and thereby stimulate the receiving cell.
32.
For example, one study found that Group I mGluRs are located mostly on postsynaptic parts of cells, while groups II and III are mostly located on presynaptic elements, though they have been found on both pre-and postsynaptic membranes.
33.
Calmodulin activates calcium / calmodulin-dependent protein kinase II ( CaMKII ), which & mdash; among other things & mdash; acts on AMPAR-containing phosphorylates these AMPARs, which serves as a signal to insert them into the postsynaptic membrane.
34.
Activation of the receptor depends on glutamate binding, D-serine or glycine binding at its NR1-linked binding site and AMPA receptor-mediated depolarization of the postsynaptic membrane, which relieves the voltage-dependent channel block by Mg 2 +.
35.
Though AMPA receptors are not expressed in the postsynaptic membranes of silent synapses, they are stored in vesicles inside the postsynaptic cells, where they cannot detect extracellular glutamate, but can be quickly inserted into the postsynaptic cell membrane in response to a tetanizing stimulus.
36.
Neurons communicate with one another at synapses, which consist of the tip of the communicating cell ( the presynpatic membrane ), the tip of the receiving cell ( the postsynaptic membrane ), and the space in between the two ( the synaptic cleft ).
37.
There are at least five major scaffold proteins that are enriched in the active zone; UNC13B / Munc13, RIMS1 ( Rab3-interacting molecule ), Bassoon, ?-neurexin, and other proteins within the complex such as Piccolo and Bassoon . ?-neurexin then binds to cell adhesion molecule, neuroligin located on the postsynaptic membrane.
38.
When the presynaptic terminal is electrically stimulated, an array of molecules embedded in the membrane are activated, and cause the contents of the vesicles to be released into the narrow space between the presynaptic and postsynaptic membranes, called the synaptic cleft . The neurotransmitter then binds to receptors embedded in the postsynaptic membrane, causing them to enter an activated state.
39.
When the presynaptic terminal is electrically stimulated, an array of molecules embedded in the membrane are activated, and cause the contents of the vesicles to be released into the narrow space between the presynaptic and postsynaptic membranes, called the synaptic cleft . The neurotransmitter then binds to receptors embedded in the postsynaptic membrane, causing them to enter an activated state.
40.
A chemical signal ( synaptic transmission ) begins with the action potential that propagates down the axon of so-called presynaptic terminal to trigger Ca 2 + influx, which causes the synaptic vesicles to fuse and release neurotransmitters, via exocytosis, to the synaptic cleft . Released neurotransmitters then bind their specific neuroreceptors at the postsynaptic membrane, or activate their specific ligand-gated ion channels, to fire an action potential that can be either excitatory or inhibitory, depending on the nature of the ligand-gated ion channel.
