Glutamate, the most prevalent excitatory neurotransmitter in the brain, has several receptors of two basic types: ionotropic and metabotropic. Mechanisms of synaptic plasticity rely heavily on certain of these receptors. Discuss in detail the structural and functional properties and the significance of the different receptors, and make clear the role of the AMPA and NMDA receptors in synaptic plasticity. Cite experimental evidence implicating these receptors in synaptic plasticity (especially in development).