Glutamates act as excitatory neurotransmitters in the brain and are essential to normal functioning. Receptor sites are either the fast-acting ionotropic types such as AMPA (i.e., α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid), which primarily activate or inhibit, or the slower acting N-methyl D-aspartate (NMDA) types, which facilitate a strengthening of the synaptic connection known as long-term potentiation. Glutamates bind with activating receptors (AMPA), resulting in fast activation of the postsynaptic neuron.