• Kynurenic acid (KYNA or KYN) is a product of the normal metabolism of amino acid L-tryptophan. (wikipedia.org)
  • It has been shown that kynurenic acid possesses neuroactive activity. (wikipedia.org)
  • As a result, kynurenic acid has been considered for use in therapy in certain neurobiological disorders. (wikipedia.org)
  • Conversely, increased levels of kynurenic acid have also been linked to certain pathological conditions. (wikipedia.org)
  • Kynurenic acid was discovered in 1853 by the German chemist Justus von Liebig in dog urine, which it was apparently named after. (wikipedia.org)
  • However, recently (2011) direct recording of α7 nicotinic acetylcholine receptor currents in adult (noncultured) hippocampal interneurons by the Cooper laboratory validated a 2009 study that failed to find any blocking effect of kynurenic acid across a wide range of concentrations, thus suggesting that in noncultured, intact preparations from adult animals there is no effect of kynurenic acid on α7 nicotinic acetylcholine receptor currents. (wikipedia.org)
  • High levels of kynurenic acid have been identified in patients suffering from tick-borne encephalitis, schizophrenia and HIV-related illnesses. (wikipedia.org)
  • 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. (wikipedia.org)
  • High levels of kynurenic acid have been identified in human urine in certain metabolic disorders, such as marked pyridoxine deficiency and deficiency/absence of kynureninase. (wikipedia.org)
  • When researchers decreased the levels of kynurenic acid in the brains of mice, their cognition was shown to improve markedly. (wikipedia.org)
  • Kynurenic acid shows neuroprotective properties. (wikipedia.org)
  • One controlled study kept mice on a ketogenic diet and measured kynurenic acid concentrations in different parts of the brain. (wikipedia.org)
  • It found that the mice on the ketogenic diet had greater kynurenic acid concentrations in the striatum and hippocampus compared to mice on a normal diet, with no significant difference in the cortex. (wikipedia.org)
  • Nicotinic α7 acetylcholine receptor-mediated currents are not modulated by the tryptophan metabolite kynurenic acid in adult hippocampal interneurons. (wikipedia.org)
  • Another tryptophan metabolite, 5-hydroxyindoleacetic acid exerts its effects via the orphan G protein-coupled receptor GPR35. (wikipedia.org)
  • For instance, excitatory amino acid receptor excitotoxicity has been implicated in the pathophysiology of numerous neurological disorders, including the etiology of cerebral deficits subsequent to cardiac bypass surgery and grafting, stroke, cerebral ischemia, spinal cord lesions resulting from trauma or inflammation, perinatal hypoxia, cardiac arrest, and hypoglycemic neuronal damage. (justia.com)
  • The excitatory amino acids are of great physiological importance, playing a role in a variety of physiological processes, such as long-term potentiation (learning and memory), the development of synaptic plasticity, motor control, respiration, cardiovascular regulation, and sensory perception. (justia.com)
  • Both types of excitatory amino acid receptor appear not only to mediate normal synaptic transmission along excitatory pathways, but also to participate in the modification of synaptic connections during development and throughout life. (justia.com)
  • Elmslie KS, Yoshikami D. (1985) Effects of kynurenate on root potentials evoked by synaptic activity and amino acids in the frog spinal cord. (wikipedia.org)
  • PMID 2257491 Grotta J, Clark W, Coull B, Pettigrew LC, Mackay B, Goldstein LB, Meissner I, Murphy D, LaRue L. Safety and tolerability of the glutamate antagonist CGS 19755 (Selfotel) in patients with acute ischemic stroke. (wikipedia.org)
  • The local infusion of 2-amino-5-phosphonovalerate (500 microM), dizocilpine (50 microM) and CNQX (100 microM), started 80 min before cocaine injection, significantly inhibited the cocaine-induced increase in extracellular dopamine. (aspetjournals.org)
  • NR2B has been associated with age- and visual-experience-dependent plasticity in the neocortex of rats, where an increased NR2B/NR2A ratio correlates directly with the stronger excitatory LTP in young animals. (wikipedia.org)
  • Examples of EAARIs include dihydrokainic acid (DHK) and WAY-213,613, selective blockers of EAAT2 (GLT-1), and L-trans-2,4-PDC, a non-selective blocker of all five EAATs. (wikipedia.org)