Eliprodil, also known as SL 82-0715, is a non-competitive NMDA glutamate receptor antagonist, which targets the polyamine modulatory site and is selective for NR2B subunit-containing receptors. Eliprodil was in phase III clinical trial for the treatment of stroke or traumatic brain injury. However, these investigations were failed. One reason suggested for failure was that eliprodil had blocked the synaptic transmission mediated by NMDA receptors, hindering neuronal survival. In addition, eliprodil has been studied in phase II clinical trials for the treatment of Parkinson's disease.

AE-37 (ANAVEX2-73, Tetrahydro-N, N-dimethyl-2, 2-diphenyl-3-furanemethanamine) is an orally available drug candidate developed to potentially modify Alzheimer’s disease rather than temporarily address its symptoms. It has a clean Phase 1 data profile and shows a reversal of memory loss (anti-amnesic properties) and neuroprotection in several models of Alzheimer’s disease. This drug is in Phase II trials for Alzheimer's disease, phase I trials for epilepsy, and in preclinical trials for amyotrophic lateral sclerosis, Parkinson's disease, Rett syndrome, stroke. AE-37 may function as a pro-drug for ANAVEX19-144 and acts as a muscarinic receptor and a moderate sigma1 receptor agonist.

Clorgiline is a monoamine oxidase (MAO) inhibitor. Specifically, it is an irreversible and selective inhibitor of MAO-A. Clorgiline was under investigation for antidepressant and anxiolytic potential but has never been marketed, likely due to efficacy concerns. It continues to see routine use as a molecular probe in biomedical research examining a number of neurological disease and cancer models. In addition to inhibiting the MAO-A receptor, it has also been found to bind to the sigma1 receptor, and with high affinity to the I2 imidazoline receptor.

SKF83959 is a benzodiazepine derivative which acts as an agonist of D1 receptor. Activation of D1 receptors by SKF83959 fails to stimulate adenylyl cyclase and inhibits the stimulation of adenylyl cyclase induced by dopamine but stimulates phosphatidylinositol 4,5-biphosphate hydrolysis in membranes of frontal cortex. SKF83959 was identified as a specific agonist for the heteromer D1/D2 complex. SKF83959 elicit anti-parkinsonism effects in monkeys and rodents. In lower concentrations, SKF83959 inhibits serotonin, norepinephrine and dopamine transporters and is an allosteric regulator of sigma 1 receptor. The compound has demonstrated activity in a preclinical model of depression.

4-{2-[5-methyl-1-(naphthalen-2-yl)-1H-pyrazol-3-yloxy]ethyl}morpholine (S1RA, E-52862) is an 1-arylpyrazole class of sigma-1 receptor antagonist. Formalin-induced nociception (both phases), capsaicin-induced mechanical hypersensitivity and sciatic nerve injury-induced mechanical and thermal hypersensitivity were dose-dependently inhibited by systemic administration of S1RA. Occupancy of sigma-1 receptors in the CNS was significantly correlated with the antinociceptive effects. As a mechanistic correlate, electrophysiological recordings demonstrated that pharmacological antagonism of sigma-1 receptors attenuated the wind-up responses in spinal cords sensitized by repetitive nociceptive stimulation. Esteve is developing E 52862 for the treatment of several pain indications, including diabetic neuropathies, chemotherapy-induced neuropathic pain, postherpetic neuralgia, postoperative pain. Phase II development of this first-in-class agent is underway in Romania, Spain and Greece.