Pellegrino R G, Spencer P S, Ritchie J M
Brain Res. 1984 Jul 9;305(2):357-60. doi: 10.1016/0006-8993(84)90442-6.
The saturable uptake of tritium-labeled saxitoxin by the rat left cervical sympathetic trunk, which consists almost entirely of unmyelinated fibers, indicates that the density of sodium channels on the axolemma of these fibers is about 200 channels/microns 2.