SYNAPSE,Synaptic contact and nerve impulse. Representation of the nerve impulse transmission of a neuron synapse A (on the top) to a dendritic button of a neuron B (on the bottom). Vesicles release glutamate (green balls) that fix on the receptors (purple) that open the sodium channels and enable the Na+ (+) ions to penetrate in the dendritic button of the neuron B, thus creating an electric current. The two pink elements are mitochondria.