AP5 (also known as APV, (2''R'')-amino-5-phosphonovaleric acid, or (2''R'')-amino-5-phosphonopentanoate) is a chemical compound used as a biochemical tool to study various cellular processes. It is a selective

NMDA receptor antagonist NMDA receptor antagonists are a class of drugs that work to receptor antagonist, antagonize, or inhibit the action of, the NMDA, ''N''-Methyl-D-aspartate receptor (NMDA receptor, NMDAR). They are commonly used as anesthetics for humans and anima ...

that competitively inhibits the ligand (glutamate) binding site of

NMDA receptor The ''N''-methyl-D-aspartate receptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and predominantly Ca2+ ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other ...

s. AP5 blocks NMDA receptors in micromolar concentrations (~50 μM). AP5 blocks the cellular analog of

classical conditioning Classical conditioning (also respondent conditioning and Pavlovian conditioning) is a behavioral procedure in which a biologically potent Stimulus (physiology), stimulus (e.g. food, a puff of air on the eye, a potential rival) is paired with a n ...

in the sea slug '' Aplysia californica'', and has similar effects on ''Aplysia''

long-term potentiation In neuroscience, long-term potentiation (LTP) is a persistent strengthening of synapses based on recent patterns of activity. These are patterns of synaptic activity that produce a long-lasting increase in signal transmission between two neuron ...

(LTP), since NMDA receptors are required for both. It is sometimes used in conjunction with the

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

chelator BAPTA to determine whether NMDARs are required for a particular cellular process. AP5/APV has also been used to study NMDAR-dependent LTP in the mammalian hippocampus.Gustafsson B., Wigström H., Abraham W.C., and Huang Y.Y. Long-Term Potentiation in the Hippocampus Using Depolarizing Current Pulses as the Conditioning Stimulus to Single Volley Synaptic Potentials. ''Journal of Neuroscience.'' 1987 March;7(3):774-780 In general, AP5 is very fast-acting within ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'' preparations, and can block NMDA receptor action at a reasonably small concentration. The active

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

of AP5 is considered to be the D configuration, although many preparations are available as a racemic mixture of D- and L-isomers. It is useful to isolate the action of other

glutamate Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a Essential amino acid, non-essential nutrient for humans, meaning that ...

receptors in the brain, i.e.,

AMPA α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, better known as AMPA, is a compound that is a specific agonist for the AMPA receptor, where it mimics the effects of the neurotransmitter glutamate Glutamic acid (symbol Glu or E; kn ...

and kainate receptors. AP5 can block the conversion of a silent synapse to an active one, since this conversion is NMDA receptor-dependent.

References

External links

* {{Ionotropic glutamate receptor modulators NMDA receptor antagonists Alpha-Amino acids Phosphonic acids

See also

References

External links