A kynurenic acid hypothesis of schizophrenia was proposed in 2007, based on its action on midbrain dopamine activity and NMDArs, thus linking dopamine hypothesis of schizophrenia with the glutamate hypothesis of the disease.
12.
In response to the studies showing detrimental behaviour following increases in kynurenic acid the authors also note that the diet was generally well tolerated by the animals, with no " gross behavioural abnormalities ".
13.
Quinolinic acid activity has been associated with neurodegenerative disorders such as Huntington's disease, the neuroprective abilities of kynurenic acid forming a counterbalance against this process, and the related excitotoxicity and similar damaging effects on neurons.
14.
Examples of APV, Amantadine, dextromethorphan ( DXM ), ketamine, magnesium, tiletamine, phencyclidine ( PCP ), riluzole, memantine, methoxetamine ( MXE ), methoxphenidine ( MXP ) and kynurenic acid; the latter is the only known endogenous antagonist.
15.
In general, receptors for small molecule neurotransmitters such as serotonin will have only one endogenous agonist, but often have many different receptor subtypes ( e . g . 13 different antagonists and inverse agonists are also known ( e . g ., kynurenic acid at the NMDA receptor ), but these are much less common.
16.
Quinolinic acid is unable to pass through the blood-brain barrier ( BBB ) and must be produced within the brain microglial cells or macrophages that have passed the BBB . While quinolinic acid cannot pass the BBB, kynurenic acid, tryptophan and 3-hydroxykynurenine do and subsequently act as precursors to the production of quinolinic acid in the brain.
