Glutamateric NMDA Receptor

Question 0

Superfamily

Answer 0

Glutamate receptors

*Found ONLY in the CNS of vertebrates

Question 1

Receptor Type

Answer 1

Ligand-gated ionotropic receptor/non-selective cation channel

Question 2

Structure

Answer 2

Tetramer of homologous subunits, 3 TM. Contains at least 7 genes

Question 3

Agonist and Co-agonist

Answer 3

Requires the binding of glutamate (agonist) and co-agonist (glycine) at the same time for activation. Interacts with AMPA receptor.
**Also Voltage dependent! Requires the depolarization of the cell to remove Mg blockage from the channel = activation

Question 4

Antagonist

Answer 4

AP5 and Memantine

Question 5

Function

Answer 5

Non-specific cation channel. Sense and mediate repetitive and excitatory synaptic activity, functions as a molecular coincidence detector for presynaptic glutamate release and postsynaptic Vm depolarization in a neuron. Plays critical role in synaptic plasticity (mechanism of learning and memory). Induces excitotoxicity as over-activated (causing excessive Ca influx that can lead to dysregulation, damage or neuron death).

Question 6

Phosphorylation

Answer 6

Increases its activity (excessive Ca influx is toxic).

Question 7

Unique Properties

Answer 7

Highly permeable to Ca
Voltage dependent - need depolarization to remove Mg blockade = activation
Needs binding of agonist and co-agonist