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Logo of jphysiolThe Journal of Physiology SiteMembershipSubmissionJ Physiol
J Physiol. Feb 1985; 359: 31–46.
PMCID: PMC1193363

Conduction velocity is related to morphological cell type in rat dorsal root ganglion neurones.


Combining intracellular recording and dye-injection techniques permitted direct correlation of neuronal soma size with peripheral nerve conduction velocity in individual neurones of the L4 dorsal root ganglion (d.r.g.) of the anaesthetized 5-8-week-old rat. The conduction velocities fell into two main groups; those greater than 14 m/s (A alpha and beta fibres) and those less than 8 m/s (A delta and C fibres). Fibres with conduction velocities in the A delta range (2.2-8 m/s) in the sciatic nerve between the sciatic notch and the neuronal soma in the d.r.g. often conducted more slowly, that is in the C-fibre range (less than 1.4 m/s), in the periphery from the tibial nerve to the sciatic notch. For the fast-conducting myelinated afferents, there was a loose positive correlation between cell size and the conduction velocity of the peripheral axon, whereas a clearer positive correlation existed between neuronal cell size and axonal conduction velocity both for A delta- and for C-fibre afferents. The relationship of the cell cross-sectional area (measured at the nucleolar level), to the cell volume for each neuronal soma was similar for the different conduction velocity groups. The somata of the fast-conducting myelinated A alpha and A beta fibres had a similar mean and range of cross-sectional areas to those of the large light cell population. The somata with A delta and C fibres were of a more uniform size and were restricted to the smaller cells within the ganglia. The mean and range of cross-sectional areas of the C cells was similar to those of the small dark cell population. A delta somata had a larger mean and range of cell sizes than those of the small dark cell population. The relationships of peripheral axon type to the morphological cell types are discussed.

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Selected References

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  • BIRREN JE, WALL PD. Age changes in conduction velocity, refractory period, number of fibers, connective tissue space and blood vessels in sciatic nerve of rats. J Comp Neurol. 1956 Feb;104(1):1–16. [PubMed]
  • Duce IR, Keen P. An ultrastructural classification of the neuronal cell bodies of the rat dorsal root ganglion using zinc iodide-osmium impregnation. Cell Tissue Res. 1977 Dec 13;185(2):263–277. [PubMed]
  • Duclaux R, Mei N, Ranieri F. Conduction velocity along the afferent vagal dendrites: a new type of fibre. J Physiol. 1976 Sep;260(2):487–495. [PMC free article] [PubMed]
  • DUN FT. The delay and blockage of sensory impulses in the dorsal root ganglion. J Physiol. 1955 Feb 28;127(2):252–264. [PMC free article] [PubMed]
  • Hökfelt T, Elde R, Johansson O, Luft R, Nilsson G, Arimura A. Immunohistochemical evidence for separate populations of somatostatin-containing and substance P-containing primary afferent neurons in the rat. Neuroscience. 1976;1(2):131–136. [PubMed]
  • Hopkins AP, Lambert EH. Age changes in conduction velocity of unmyelinated fibers. J Comp Neurol. 1973 Feb 15;147(4):547–552. [PubMed]
  • Horch KW, Tuckett RP, Burgess PR. A key to the classification of cutaneous mechanoreceptors. J Invest Dermatol. 1977 Jul;69(1):75–82. [PubMed]
  • IGGO A. The electrophysiological identification of single nerve fibres, with particular reference to the slowest-conducting vagal afferent fibres in the cat. J Physiol. 1958 Jun 18;142(1):110–126. [PMC free article] [PubMed]
  • Iggo A, Ogawa H. Primate cutaneous thermal nociceptors. J Physiol. 1971 Jul;216(2):77P–78P. [PubMed]
  • Lawson SN. The postnatal development of large light and small dark neurons in mouse dorsal root ganglia: a statistical analysis of cell numbers and size. J Neurocytol. 1979 Jun;8(3):275–294. [PubMed]
  • Lawson SN, Biscoe TJ. Development of mouse dorsal root ganglia: an autoradiographic and quantitative study. J Neurocytol. 1979 Jun;8(3):265–274. [PubMed]
  • Lawson SN, Caddy KW, Biscoe TJ. Development of rat dorsal root ganglion neurones. Studies of cell birthdays and changes in mean cell diameter. Cell Tissue Res. 1974;153(3):399–413. [PubMed]
  • Lawson SN, Harper AA, Harper EI, Garson JA, Anderton BH. A monoclonal antibody against neurofilament protein specifically labels a subpopulation of rat sensory neurones. J Comp Neurol. 1984 Sep 10;228(2):263–272. [PubMed]
  • Lynn B, Carpenter SE. Primary afferent units from the hairy skin of the rat hind limb. Brain Res. 1982 Apr 22;238(1):29–43. [PubMed]
  • Nagy JI, Hunt SP. Fluoride-resistant acid phosphatase-containing neurones in dorsal root ganglia are separate from those containing substance P or somatostatin. Neuroscience. 1982 Jan;7(1):89–97. [PubMed]
  • Spencer PS, Raine CS, Wiśniewski H. Axon diameter and myelin thickness. Unusual relationships in dorsal root ganglia. Anat Rec. 1973 Jun;176(2):225–243. [PubMed]
  • Stewart WW. Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthalimide tracer. Cell. 1978 Jul;14(3):741–759. [PubMed]
  • Wässle H, Levick WR, Kirk DL, Cleland BG. Axonal conduction velocity and perikaryal size. Exp Neurol. 1975 Oct;49(1 Pt 1):246–251. [PubMed]
  • Yamadori T. A light and electron microscopic study on the postnatal development of spinal ganglia in rats. Kaibogaku Zasshi. 1970 Aug 1;45(4):191–205. [PubMed]
  • Yoshida S, Matsuda Y. Studies on sensory neurons of the mouse with intracellular-recording and horseradish peroxidase-injection techniques. J Neurophysiol. 1979 Jul;42(4):1134–1145. [PubMed]
  • Zenker W, Högl E. The prebifurcation section of the axon of the rat spinal ganglion cell. Cell Tissue Res. 1976 Jan 27;165(3):345–363. [PubMed]

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