Fig. 4

Potentiation procedures for a chemical synapse. The presynaptic activation releases glutamate neurotransmitters (Glu) that bind to NMDAR and AMPAR. Only the AMPAR opens the ion channels for monovalent cations (e.g. Na⁺) when the postsynaptic neuron is at rest state or polarized, while NMDAR opens the voltage-gated channels to allow Ca²⁺ to diffuse once the postsynaptic neuron is depolarized or activated. Reprinted with permission from [53]