part_of part of part of independent continuant cellular_component axon presynaptic cell presynaptic terminal GO:0043195 pre-synaptic terminal Planarian_Anatomy Terminal inflated portion of the axon, containing the specialized apparatus necessary to release neurotransmitters. The axon terminus is considered to be the whole region of thickening and the terminal bouton is a specialized region of it. https://orcid.org/0000-0003-2569-1939 | https://orcid.org/0000-0002-7535-4819 PMID:23903188