terminal bouton type I terminal bouton GO:0061174 type I terminal button Terminal inflated portion of the axon of a glutamatergic neuron, containing the specialized apparatus necessary to release neurotransmitters that will induce the contraction of muscle. The axon terminus is considered to be the whole region of thickening and the terminal bouton is a specialized region of it. cellular_component dph 2010-07-13T09:13:05Z