Quisqualamine is the α-decarboxylated analogue of

quisqualic acid Quisqualic acid is an agonist of the AMPA, kainate, and group I metabotropic glutamate receptors. It is one of the most potent AMPA receptor agonists known. It causes excitotoxicity and is used in neuroscience to selectively destroy neurons ...

, as well as a relative of the

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotra ...

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 ...

and

γ-aminobutyric acid GABA (gamma-aminobutyric acid, γ-aminobutyric acid) is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GA ...

(GABA). α-Decarboxylation of

excitatory amino acid An amino acid neurotransmitter is an amino acid which is able to transmit a nerve message across a synapse. Neurotransmitters (chemicals) are packaged into vesicles that cluster beneath the axon terminal membrane on the presynaptic side of a s ...

s can produce derivatives with

inhibitory An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a Chemical synapse, postsynaptic neuron less likely to generate an action potential.Purves et al. Neuroscience. 4th ed. Sunderland (MA): Sinauer Associates, Inc ...

effects. Indeed, unlike quisqualic acid, quisqualamine has central depressant and

neuroprotective Neuroprotection refers to the relative preservation of neuronal structure and/or function. In the case of an ongoing insult (a neurodegenerative insult) the relative preservation of neuronal integrity implies a reduction in the rate of neuronal l ...

properties and appears to act predominantly as an

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

of the GABA_A receptor and also to a lesser extent as an agonist of the

glycine receptor The glycine receptor (abbreviated as GlyR or GLR) is the receptor Receptor may refer to: * Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochem ...

, due to the facts that its actions are inhibited ''

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 ...

'' by GABA_A

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.bicuculline Bicuculline is a phthalide-isoquinoline compound that is a light-sensitive competitive antagonist of GABAA receptors. It was originally identified in 1932 in plant alkaloid extracts and has been isolated from ''Dicentra cucullaria'', '' Adlumia ...

and

picrotoxin Picrotoxin, also known as cocculin, is a poisonous crystalline plant compound. It was first isolated by the French pharmacist and chemist Pierre François Guillaume Boullay (1777–1869) in 1812. The name "picrotoxin" is a combination of the Gree ...

and by the

glycine Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (G ...

antagonist

strychnine Strychnine (, , American English, US chiefly ) is a highly toxicity, toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, ...

, respectively. Mg²⁺ and DL-AP5,

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 ...

blockers,

CNQX CNQX or cyanquixaline (6-cyano-7-nitroquinoxaline-2,3-dione) is a competitive AMPA/ kainate receptor antagonist. Its chemical formula is C9H4N4O4. CNQX is often used in the retina to block the responses of OFF-bipolar cells for electrophysiology ...

, an antagonist of both the

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 receptor Kainate receptors, or kainic acid receptors (KARs), are ionotropic receptors that respond to the neurotransmitter glutamate. They were first identified as a distinct receptor type through their selective activation by the agonist kainate, a dr ...

s, and 2-hydroxysaclofen, a GABA_B receptor antagonist, do not affect quisqualamine's actions ''in vitro'', suggesting that it does not directly affect the

ionotropic glutamate receptor Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that are activated by the neurotransmitter glutamate. They mediate the majority of excitatory synaptic transmission throughout the central nervous system and are key players in ...

s or the GABA_B receptor in any way. Whether it binds to and acts upon any of the

metabotropic glutamate receptor The metabotropic glutamate receptors, or mGluRs, are a type of glutamate receptor that are active through an indirect metabotropic receptor, metabotropic process. They are members of the group C GPCR family, group C family of G-protein-coupled r ...

s like its analogue quisqualic acid however is unclear.

References

Amines Anticonvulsants Ureas Oxadiazolidines Carbamates Glycine receptor agonists GABAA receptor agonists {{nervous-system-drug-stub

See also

References