Stimulus intensity-dependent recruitment of NaV1 subunits in action potential initiation in nerve terminals of vagal C-fibers innervating the esophagus
2020 ◽
Vol 319
(4)
◽
pp. G443-G453
Keyword(s):
C Fibers
◽
We report that pharmacologically distinguishable voltage-gated sodium channels (NaV1) mediate action potential initiation at low (innocuous) versus high (noxious) intensity of esophageal distention in nerve terminals of vagal nodose C-fibers. Action potential initiation at low intensity is entirely dependent on NaV1.7; however, additional tetrodotoxin (TTX)-sensitive NaV1s are recruited at higher intensity of distention. This is the first demonstration that NaV1s underlying action potential initiation in visceral C-fibers depend on the intensity of the stimulus.