Metabotropic glutamate receptors (mGluRs), mediate excitatory synaptic transmission in the central nervous system. Potent and selective antagonists of the type I mGluRs (mGluR1 and mGluR5) are of interest as novel therapeutics for the treatment of various CNS disorders, such as pain, epilepsy, and stroke. NPS 2390 is a first generation quinoxaline derivative that acts as a noncompetitive antagonist of mGluR1 and mGluR5 with IC50 values equal to 5.2 and 82 nM, respectively). At concentrations up to 30 μM, NPS 2390 does not affect mGluR2 or mGluR8 or a standard collection of 37 additional receptors, ion channels, and enzymes. At a dose of 10 mg/kg, NPS 2390 displaced the specifically bound mGlu1R-selective antagonist, [3H]R214127, in rat cerebellum.
