commissure vs nerve tract

commissure and nerve tract both are nouns.

Word	Noun	Adjective	Verb	Adverb
commissure	Yes	No	No	No
nerve tract	Yes	No	No	No

As nouns, nerve tract is a hypernym of commissure; that is, nerve tract is a word with a broader meaning than commissure:

commissure: a bundle of nerve fibers passing from one side to the other of the brain or spinal cord
nerve tract: a bundle of myelinated nerve fibers following a path through the brain

Other hypernyms of commissure include nerve pathway, pathway, tract.

commissure (noun)	nerve tract (noun)
a bundle of nerve fibers passing from one side to the other of the brain or spinal cord	a bundle of myelinated nerve fibers following a path through the brain