A quantitative analysis of isotope concentration profiles and rapid transport velocities in the C-fibers of the garfish olfactory nerve.

In the olfactory nerve of the long-nosed garfish (Lepisosteus osseus), unusually well-defined isotope concentration distributions can be established with the rapid transport process. Transport velocities of two profile loci can be accurately described and a quantitative profile analysis is possible after profile normalization. Results from such studies indicate that: (1) peak amplitudes decrease exponentially as a function of distance from the olfactory mucosa according to the equation p = 2130 exp (-0.109chi); (2) the wavefront base and the peak apex loci move at rates of 221 +/- 2 and 201 +/- 4 mm/day, respectively (at 23 degrees C), revealing a peak dispersion or broadening during transport; (3) the broadening is asymmetric with material shifting to the rear of the peak; (4) plateau regions are established behind the peak with material deposited by the peak; (5) only 20% of the total radioactivity in a cut nerve reaches the nerve terminals in the rapid transport peak while 80% is deposited along the axon; (6) profile areas from cut nerves decrease and lose 15% of their activity in 20 hr, while intact nerve profiles increase 10% in 16 hr due to continued somal contribution to the profile; (7) the displacement of the wavefront base (WFB) and peak apex (PA) profile loci can be described by the functions s(WFB) = (0.055T - 0.345)t - 1.43 s(PA) = (0.053T - 0.391)t - 2.71 (8) transport velocities are linear functions of temperature between 10 and 25 degrees C and increase 370% in that range. A linear extrapolation of the WFB and PA functions to 37 degrees C yields 410 and 377 mm/day, respectively.