L-701,324 [7-chloro-4-hydroxy-3(3-phenoxy) phenylquinoline-2-(H)-one] is a selective and full antagonist at the glycine site of the NMDA receptor, has been studied on animals as potential antipsychotic and anticonvulsant agent. But these studies were discontinued.

1,12-Dodecanediamine (Dytek-12) is a 12 carbon aliphatic diamine. It is a highly versatile polymer monomer and chemical intermediate that is useful in the manufacture of a variety of products.

LY235959 is the active isomer of the 6-substituted decahydroisoquinoline-3-carboxylic acid, LY274614. Both LY274614 and LY235959 have demonstrated potent NMDA receptor antagonist activity both in vivo and in-vitro. LY235959 has been shown to attenuate and reverse morphine tolerance as well as, attenuate opioid withdrawal and block c-fos mRNA induction in limbic areas. The attenuation of morphine tolerance occurs through the interaction of LY235959 with the NMDA receptor and not by producing opiate receptor changes. LY235959 is able to block NMDA receptor-induced hyperalgesia, as well as formalin-induced inflammatory pain, in rats. These antinociceptive effects of LY235959 were obtained at doses that did not produce motor impairment. LY235959 does not block the hyperalgesia produced by kainic acid (a non-NMDA glutamate receptor agonist) providing evidence of its selectivity for the NMDA receptor.

Domoic acid is one of the best-known marine toxins, causative of important neurotoxic alterations. In the year 1987, domoic acid was responsible for four deaths and the illness of more than 100 people after consuming blue mussels (Mytilus edulis) harvested in the Cardigan Bay of Prince Edward Island, Canada. The symptomatology comprised three kinds of signs: gastrointestinal (nausea, vomiting,), cardiovascular (unstable blood pressure and arrhythmias), and neurological signs (disorientation, confusion, hallucinations, coma, and memory impairment). After this event was discovered the domoic acid epileptic. Nearly a year after the amnesic shellfish poisoning event, an 84 years old male survivor re-experienced severe seizures and was diagnosed with temporal lobe epilepsy caused by domoic acid intoxication. This toxin has a high affinity for the glutamate receptors (GluRs) subtypes: alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and KA receptors. The binding of domoic acid to receptors provokes an increase of calcium (Ca2+) levels, causing the release of Glu to the extracellular space, and the activation of N-methyl-d-aspartate (NMDA) receptors. The histological consequences of these cellular alterations comprise astrocytosis, cytoskeletal disarrangement and, finally, cell death.

D-alanine is an isomer of non-essential L-amino acid. D isomer is found in the cell walls of bacteria, but not in bacterial proteins. It was discovered, that being an endogenous agonist of the glycine site of the N-methyl-d-aspartate (NMDA) receptor, D-alanine can have beneficial effects on schizophrenia.

N,N-dimethylglycine or dimethylglycine (DMG) is an amino acid derivative found in the cells of all plants and animals and can be obtained in the diet in small amounts from grains and meat. The human body produces DMG when metabolizing choline into glycine. DMG has been found acting at glycine binding site of the N-methyl-d-aspartate receptor (NMDAR). DMG has had wide acceptance as a nonfuel nutrient; presumably it enhances oxygen utilization by tissue and complexes free radicals. There were published studies, which have shown little to no difference between DMG treatment and placebo in autism spectrum disorders and the same no effect was observed in case of investigated DMG for epilepsy. This compound was also suggested to use to improve the athletic performance enhancer, but this usage was ineffective as well.

24S-hydroxycholesterol (24(S)-HC), the major cholesterol metabolite in the brain, is critical to brain cholesterol metabolism and turnover. This metabolite is a very potent, direct, and selective positive allosteric modulator of N-methyl-D-aspartate receptors (NMDARs) with a mechanism that does not overlap that of other allosteric modulators. NMDARs are glutamate-gated ion channels that are critical to the regulation of excitatory synaptic function in the CNS. It is known, that concentrations of 24(S)-HC in plasma and cerebrospinal fluid (CSF) are significantly higher in Alzheimer's disease and in mild cognitive impairment patients at early stages of the diseases compared to healthy subjects. It was suggested, that 24-hydroxycholesterol, could be a sensitive biomarker for the evaluation of these two diseases.

Epipregnanolone is an epimer of endogenous neurosteroid pregnanolone, it has been shown to antagonize GABAA and NMDA receptors. In addition epipregnanolone inhibits calcium T-currents and stimulates TRPM3 channel. Epipregnanolone displays anesthetic properties. Epipregnanolone has been shown to reduce alcohol self-administration in rats.