7-Chlorokynurenic acid (7-CKA), a derivative of kynurenic acid, is a potent and selective antagonist of the N-methyl-D-aspartate (NMDA) receptor. 7-CKA acts and binds with high affinity to the glycine binding site located on the NMDA receptor. This compound has neuroprotective, antinociceptive and anticonvulsive effects lacking the ability to penetrate the blood-brain-barrier and has therapeutic potential in some types of epilepsy^1-3. Several studies that conducted radioligand binding experiments showed that 7-chlorokynurenic acid binds to the strychnine-glycine binding site with high affinity (IC₅₀ value of 0.56 μM)⁵_.

Several studies have shown that acute administration of 7-CKA can produce rapid antidepressant-like effects without showing addictive potential². It seems that inhibition of the phospho-glycogen synthase kinase-3β pathway and activation of the mammalian target of rapamycin in the medial prefrontal cortex are connected to the 7-CKA rapid behavioural response².

NMDA receptors play an important role in a variety of cellular processes and brain functions such as synaptic plasticity, addiction and stroke. NMDA receptors mediate several physiological functions including learning and memory formation, they play a role in glutamate excitotoxicity and are involved in many neurodegenerative conditions including Alzheimer’s disease⁴.