What does PSD-95 stand for?
postsynaptic density protein 95
PSD-95 (postsynaptic density protein 95) also known as SAP-90 (synapse-associated protein 90) is a protein that in humans is encoded by the DLG4 (discs large homolog 4) gene. PSD-95 is a member of the membrane-associated guanylate kinase (MAGUK) family.
Where is PSD-95 located?
At the PSD, PSD-95 has been identified with EM tomography and by immunolabeling of its N and C terminal ends (Chen et al., 2008b). It appears that PSD-95 N-termini are at the membrane and C-termini are away from the membrane (Chen et al., 2011, 2015; Jeyifous et al., 2016).
Does LTP require AMPA?
Long-term potentiation (LTP) of excitatory synaptic strength, which has long been considered a synaptic correlate for learning and memory, requires a fast recruitment of additional α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors (AMPARs) to the postsynaptic sites.
What is the role of AMPA in LTP?
Following LTP induction, AMPARs are rapidly trafficked into these “silent synapses” and contribute to the depolarization of the postsynaptic neuron (Isaac et al., 1995; Liao et al., 1995).
What do Synaptosomes do?
Synaptosomes are commonly used to study synaptic transmission in the test tube because they contain the molecular machinery necessary for the uptake, storage, and release of neurotransmitters. In addition they have become a common tool for drug testing.
What activates AMPA?
Glutamate binds to postsynaptic AMPARs and another glutamate receptor, the NMDA receptor (NMDAR). Ligand binding causes the AMPARs to open, and Na+ flows into the postsynaptic cell, resulting in a depolarization.
How is AMPA activated?
Activation of AMPA receptors induces sodium influx through the channels, which in turn overcomes the voltage-dependent Mg++ blockade of NMDA receptors. The calcium influx resulting from this triggers a series of signal transduction cascades involving kinases, phosphatases, and scaffolding proteins.
How do AMPA and NMDA work together?
The AMPA receptor is paired with an ion channel so that when glutamate binds to this receptor, this channel lets sodium ions enter the post-synaptic neuron. The NMDA receptor is also paired with an ion channel, but this channel admits calcium ions into the post-synaptic cell.
What is the difference between AMPA and NMDA receptors?
The main difference between AMPA and NMDA is that only the sodium and potassium influx occur in AMPA receptors whereas, in NMDA receptors, calcium influx occurs in addition to sodium and potassium influx. They are nonselective, ligand-gated ion channels, which mainly allow the passage of sodium and potassium ions.
What is a Synaptoneurosome?
The synaptoneurosome is a composite particle containing one or more presynaptic compartments (synaptosome) attached to a postsynaptic element (neurosome) [1]. In the synaptodendrosome, the axon terminal adheres to a larger portion of the postsynaptic compartment (dendrite) (see Dendrite) [2].
What is a synapse?
synapse, also called neuronal junction, the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector). Electrically charged ions then flow through the channels into or out of the neuron.
Are AMPA receptors blocked by magnesium?
The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA and kainate receptors. Extracellular magnesium (Mg2+) and zinc (Zn2+) ions can bind to specific sites on the receptor, blocking the passage of other cations through the open ion channel.