This is any condition in which the main influencing factor is 2-methyl-6-(phenylethynyl)pyridine, a methylpyridine that consists of 2-methylpyridine bearing an additional phenylethynyl group at position 6. It is a potent and highly selective non-competitive antagonist at the mGlu5 receptor subtype (IC50 = 36 nM) and a positive allosteric modulator at mGlu4 receptors. It functions as an excitatory amino acid antagonist and an anxiolytic agent.