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.[5]
(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.[6]
^Vartanian MG, Taylor CP (Nov 1991). "Different stereoselectivity of the enantiomers of HA-966 (3-amino-1-hydroxy-2-pyrrolidinone) for neuroprotective and anticonvulsant actions in vivo". Neuroscience Letters. 133 (1): 109–12. doi:10.1016/0304-3940(91)90069-6. PMID1838797. S2CID36483282.
^Dunn RW, Flanagan DM, Martin LL, Kerman LL, Woods AT, Camacho F, Wilmot CA, Cornfeldt ML, Effland RC, Wood PL, et al. (Apr 1992). "Stereoselective R-(+) enantiomer of HA-966 displays anxiolytic effects in rodents". European Journal of Pharmacology. 214 (2–3): 207–14. doi:10.1016/0014-2999(92)90120-S. PMID1355434.
^Näsström J, Karlsson U, Post C (Feb 1992). "Antinociceptive actions of different classes of excitatory amino acid receptor antagonists in mice". European Journal of Pharmacology. 212 (1): 21–9. doi:10.1016/0014-2999(92)90067-E. PMID1313371.
^Singh L, Menzies R, Tricklebank MD (Sep 1990). "The discriminative stimulus properties of (+)-HA-966, an antagonist at the glycine/N-methyl-D-aspartate receptor". European Journal of Pharmacology. 186 (1): 129–32. doi:10.1016/0014-2999(90)94069-A. PMID2149338.