Intermediate
Technical
IVT
bouton
Pronunciation: boo-TOHN
Swollen terminal or en passant enlargement of an axon containing synaptic vesicles.
Full Definition
A bouton is a specialized axonal enlargement that serves as a presynaptic terminal or intermediate swelling along an axon. These structures contain high concentrations of synaptic vesicles, mitochondria, and release machinery necessary for neurotransmission. Boutons can be terminal (at axon endings) or en passant (along the axon shaft), and their morphology varies significantly across different neuron types and brain regions.
Usage
Usage note: From French 'button' - maintain italicization in some style guides when used as borrowed terminology.
In Context
- "Large mossy fiber boutons formed complex synapses with CA3 pyramidal neurons." — Hippocampal connectivity study
- "En passant boutons were identified along the entire length of the GABAergic axon." — Interneuron morphology paper
Also known as
synaptic bouton
terminal bouton
axon terminal
Don't confuse with
varicosity
growth cone