A highly selective non-competitive antagonist for the metabotropic glutamate mGlu 5 receptor subtype; displays an IC 50 value of 0.3 μ M? at hmGlu 5 , compared with > 100 μ M at hmGlu 1b , hmGlu 2 , hmGlu 6 , hmGlu 7 and hmGlu 8 . Centrally active upon systemic administration in vivo . Positive allosteric modulator at mGlu 4 receptors.
