AIDA, or 1-aminoindan-1,5-dicarboxylic acid, is a selective antagonist of mGluR (the group I metabotropic glutamate receptor). AIDA is described to competitively antagonize the stimulatory response of glutamate in cells transfected with mGluR-1a. AIDA has been used as a tool for elucidating the role of mGluR-1 receptors in various processes, where antagonism by AIDA has identified participation of the mGluR-1in hippocampus-dependent learning tasks.