The excitatory amino acid, glutamate (Glu), plays a pivotal role in many biological processes such as neuronal plasticity, memory and learning as well as in neuronal degeneration. 1 Glutamate interacts with two families of receptors, the ionotropic glutamate receptors and the metabotropic glutamate receptors, each of which is composed of several subtypes. 2. and 3. In recent years, research has been focusing on the design and synthesis of new ligands that ...