Anxiolytic properties of 1-aminocyclopropanecarboxylic acid, a ligand at strychnine-insensitive glycine receptors.

The effects of 1-aminocyclopropanecarboxylic acid were investigated on performance in an elevated plus-maze. This compound is a high-affinity, partial agonist ligand at strychnine-insensitive glycine receptors of the N-methyl-D-aspartate receptor complex. Like chlordiazepoxide, 1-aminocyclopropanecarboxylic acid increased in a dose-dependent manner both the percent entries into and the percent time spent in the open arms of the plus-maze. However, 1-aminocyclopropanecarboxylic acid was significantly less efficacious than chlordiazepoxide in these measures and increased, while chlordiazepoxide decreased, the time spent in the middle platform of the plus-maze. These findings indicate that ligands acting through strychnine-insensitive glycine receptors on the N-methyl-D-aspartate receptor complex may represent a new class of anxiolytic agents with a profile which differs from the benzodiazepines.