ha-966 ha-966 ha-966 or (±) 3-amino-1-hydroxy-pyrrolidin-2-one is a molecule used in scientific research as a glycine receptor and nmda receptor antagonist / low efficacy partial agonist. it has neuroprotective and anticonvulsant, anxiolytic, antinociceptive and sedative / hypnotic effects in animal models. pilot human clinical trials in the early 1960s showed that ha-966 appeared to benefit patients with tremors of extrapyramidal origin. ha-966identifiers iupac name 3-amino-1-hydroxy-pyrrolidin-2-one cas number1003-51-6pubchem cid1232chemspider1195uniif2jlv9220tcomptox dashboard (epa)dtxsid90905333 echa infocard100.162.446 chemical and physical dataformulac4h8n2o2molar mass116.120 g·mol−13d model (jsmol)interactive image smiles o=c1c(ccn1o)n inchi inchi=1s/c4h8n2o2/c5-3-1-2-6(8)4(3)7/h3,8h,1-2,5h2key:hckubnlzmkaein-uhfffaoysa-n the two enantiomers of ha-966 have differing pharmacological activity. the glycine/n-methyl-d-aspartate receptor antagonist activity is specific to the r-(+) enantiomer, whereas the sedative and ataxic effects are specific to the s-(-) enantiomer. r-(+)-ha-966 did not induce drug-appropriate responding in animals trained to discriminate phencyclidine (pcp) from saline, suggesting that the glycine receptor ligand r-(+)-ha-966 has a significantly different behavioral profile than drugs affecting the ion channel of the nmda receptor complex. s-(−)-ha-966 has been described as a "γ-hydroxybutyric acid (ghb)-like agent" and a "potent y-butyrolactone-like sedative", but it shows no affinity for the gabab receptor (gababr).