Conduction of nervous impulses in spinal roots and peripheral nerves of dystrophic mice
Rasminsky, M.; Kearney, R.E.; Aguayo, A.J.; Bray, G.M.
Brain Research 143(1): 71-85
ISSN/ISBN: 0006-8993 PMID: 630405 DOI: 10.1016/0006-8993(78)90753-9
Conduction was studied in the sacral ventral roots and ventral tail nerves of dystrophic mice (dy/dy) and phenotypically normal littermates. In myelinated ventral root fibers of normal mice, conduction velocity was uniform with internodal conduction time 45 .+-. 5 .mu.s (26.degree. C). In ventral root fibers of dystrophic mice, conduction velocity was decreased and strikingly non-uniform; both saltatory and continuous conduction were observed in different portions of the same nerve fiber. Continuous conduction with velocity < 2 m/s (26.degree. C) was characteristically observed in mid-root where the axons are bare; conduction was saltatory close to the exit from the spinal canal and near the spinal cord where the axons are myelinated. Maximum conduction velocity in ventral tail nerves was 21 .+-. 3 m/s for dystrophic mice and 31 .+-. 4 m/s for littermate controls (37.degree. C). Internodal lengths were somewhat decreased in the dystrophic peripheral nerves but there was no significant difference in maximum fiber diameters, myelin thickness or nodal morphology between dystrophic and normal nerves.