A-841720 is a potent, selective, and non-competitive antagonist of the mGlu1 receptor, exhibiting an IC 50 value of 10 nM specifically for the human mGlu1 receptor. It demonstrates a 34-fold greater selectivity for mGlu1 over mGlu5 (IC 50 of 342 nM), with negligible activity across a spectrum of other neurotransmitter receptors, ion channels, and transporters. Additionally, A-841720 possesses analgesic potential within a certain dose range [1] [2].