English: This illustration shows a fragment of a glutamatergic synapse. It highlights a few spherical pre-synaptic vesicles that carry the neurotransmitter glutamate (shown in pink in the cross-section). The pre-synaptic and post-synaptic membranes are shown with proteins relevant for transmitting and modulating the neuronal signal. The images of the proteins were created based on expreimentally-determined structures from the Protein Data Bank, with access codes provided. The pre-synaptic membrane features the voltage-gated sodium channel (green; 5x0m, 6j8j), the voltage-gated potassium channel (purple; 6pbx), the sodium-potassium pump (blue; 2zxe), the voltage-gated calcium channel (orange; 6jp5), and opioid receptor with G protein (aqua with dark orange and green; 4dkl). The post-synaptic membrane features in addition the glutamate (AMPA) receptor (navy blue; 5wek), and adenylyl cyclase (yellow; 6r3q). Potassium is shown in magenta, sodium in lime green, and calcium in cyan.