Complex sentence: Quisqualic acid is an agonist of the AMPA, kainate, and group I metabotropic glutamate receptors, and one of the most potent AMPA receptor agonists known.
Split into simpler sentences: Quisqualic acid is an agonist of the AMPA, kainate, and group I metabotropic glutamate receptors. It is one of the most potent AMPA receptor agonists known.